Normalment, una matriu és una col·lecció d'elements de tipus similar que té una ubicació de memòria contigua.
Matriu Java és un objecte que conté elements d'un tipus de dades similar. A més, els elements d'una matriu s'emmagatzemen en una ubicació de memòria contigua. És una estructura de dades on emmagatzemem elements similars. Només podem emmagatzemar un conjunt fix d'elements en una matriu Java.
La matriu a Java es basa en un índex, el primer element de la matriu s'emmagatzema a l'índex 0, el segon element s'emmagatzema al primer índex i així successivament.
A diferència de C/C++, podem obtenir la longitud de la matriu utilitzant el membre de longitud. En C/C++, hem d'utilitzar l'operador sizeof.
A Java, array és un objecte d'una classe generada dinàmicament. La matriu Java hereta la classe Object i implementa les interfícies serialitzables i clonables. Podem emmagatzemar valors o objectes primitius en una matriu en Java. Igual que C/C++, també podem crear matrius monodimensionals o multidimensionals en Java.
A més, Java proporciona la funció de matrius anònimes que no està disponible en C/C++.
Avantatges
Desavantatges
Tipus de matriu en java
Hi ha dos tipus de matriu.
- Matriu unidimensional
- Matriu multidimensional
Matriu unidimensional en Java
Sintaxi per declarar una matriu en Java
git add --all
dataType[] arr; (or) dataType []arr; (or) dataType arr[];
Instanciació d'una matriu en Java
arrayRefVar=new datatype[size];
Exemple de matriu Java
Vegem l'exemple senzill de matriu java, on declararem, instanciarem, inicialitzarem i recorrerem una matriu.
//Java Program to illustrate how to declare, instantiate, initialize //and traverse the Java array. class Testarray{ public static void main(String args[]){ int a[]=new int[5];//declaration and instantiation a[0]=10;//initialization a[1]=20; a[2]=70; a[3]=40; a[4]=50; //traversing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 20 70 40 50 </pre> <hr> <h2>Declaration, Instantiation and Initialization of Java Array</h2> <p>We can declare, instantiate and initialize the java array together by:</p> <pre> int a[]={33,3,4,5};//declaration, instantiation and initialization </pre> <p>Let's see the simple example to print this array.</p> <pre> //Java Program to illustrate the use of declaration, instantiation //and initialization of Java array in a single line class Testarray1{ public static void main(String args[]){ int a[]={33,3,4,5};//declaration, instantiation and initialization //printing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 33 3 4 5 </pre> <h2>For-each Loop for Java Array</h2> <p>We can also print the Java array using <strong> <a href="/java-each-loop-enhanced">for-each loop</a> </strong> . The Java for-each loop prints the array elements one by one. It holds an array element in a variable, then executes the body of the loop.</p> <p>The syntax of the for-each loop is given below:</p> <pre> for(data_type variable:array){ //body of the loop } </pre> <p>Let us see the example of print the elements of Java array using the for-each loop.</p> <pre> //Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} </pre> <p>Output:</p> <pre> 33 3 4 5 </pre> <hr> <h2>Passing Array to a Method in Java</h2> <p>We can pass the java array to method so that we can reuse the same logic on any array.</p> <p>Let's see the simple example to get the minimum number of an array using a method.</p> <pre> //Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> 3 </pre> <h2>Anonymous Array in Java</h2> <p>Java supports the feature of an anonymous array, so you don't need to declare the array while passing an array to the method.</p> <pre> //Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread 'main' java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let's see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+' '); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+' '); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+' '); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+' '); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)></pre></a.length;i++)></pre></a.length;i++)> Declaració, Instanciació i Inicialització de Java Array
Podem declarar, instanciar i inicialitzar la matriu java junts mitjançant:
int a[]={33,3,4,5};//declaration, instantiation and initialization Vegem un exemple senzill per imprimir aquesta matriu.
//Java Program to illustrate the use of declaration, instantiation //and initialization of Java array in a single line class Testarray1{ public static void main(String args[]){ int a[]={33,3,4,5};//declaration, instantiation and initialization //printing array for(int i=0;i <a.length;i++) length is the property of array system.out.println(a[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 33 3 4 5 </pre> <h2>For-each Loop for Java Array</h2> <p>We can also print the Java array using <strong> <a href="/java-each-loop-enhanced">for-each loop</a> </strong> . The Java for-each loop prints the array elements one by one. It holds an array element in a variable, then executes the body of the loop.</p> <p>The syntax of the for-each loop is given below:</p> <pre> for(data_type variable:array){ //body of the loop } </pre> <p>Let us see the example of print the elements of Java array using the for-each loop.</p> <pre> //Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} </pre> <p>Output:</p> <pre> 33 3 4 5 </pre> <hr> <h2>Passing Array to a Method in Java</h2> <p>We can pass the java array to method so that we can reuse the same logic on any array.</p> <p>Let's see the simple example to get the minimum number of an array using a method.</p> <pre> //Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> 3 </pre> <h2>Anonymous Array in Java</h2> <p>Java supports the feature of an anonymous array, so you don't need to declare the array while passing an array to the method.</p> <pre> //Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread 'main' java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let's see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)></pre></a.length;i++)> For-each Loop per a matriu Java
També podem imprimir la matriu Java utilitzant per a cada bucle . El bucle de Java for-each imprimeix els elements de la matriu un per un. Conté un element de matriu en una variable i després executa el cos del bucle.
La sintaxi del bucle for-each es mostra a continuació:
for(data_type variable:array){ //body of the loop } Vegem l'exemple d'impressió dels elements de la matriu Java utilitzant el bucle for-each.
//Java Program to print the array elements using for-each loop class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; //printing array using for-each loop for(int i:arr) System.out.println(i); }} Sortida:
33 3 4 5
Passant matriu a un mètode en Java
Podem passar la matriu java al mètode perquè puguem reutilitzar la mateixa lògica en qualsevol matriu.
Vegem un exemple senzill per obtenir el nombre mínim d'una matriu mitjançant un mètode.
//Java Program to demonstrate the way of passing an array //to method. class Testarray2{ //creating a method which receives an array as a parameter static void min(int arr[]){ int min=arr[0]; for(int i=1;iarr[i]) min=arr[i]; System.out.println(min); } public static void main(String args[]){ int a[]={33,3,4,5};//declaring and initializing an array min(a);//passing array to method }} Prova-ho ara Sortida:
3
Matriu anònim a Java
Java admet la funció d'una matriu anònima, de manera que no cal que la declareu mentre passeu una matriu al mètode.
//Java Program to demonstrate the way of passing an anonymous array //to method. public class TestAnonymousArray{ //creating a method which receives an array as a parameter static void printArray(int arr[]){ for(int i=0;i <arr.length;i++) system.out.println(arr[i]); } public static void main(string args[]){ printarray(new int[]{10,22,44,66}); passing anonymous array to method }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 22 44 66 </pre> <h2>Returning Array from the Method</h2> <p>We can also return an array from the method in Java.</p> <pre> //Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread 'main' java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let's see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)></pre></arr.length;i++)> Matriu de retorn del mètode
També podem retornar una matriu del mètode a Java.
//Java Program to return an array from the method class TestReturnArray{ //creating method which returns an array static int[] get(){ return new int[]{10,30,50,90,60}; } public static void main(String args[]){ //calling method which returns an array int arr[]=get(); //printing the values of an array for(int i=0;i <arr.length;i++) system.out.println(arr[i]); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 10 30 50 90 60 </pre> <h2>ArrayIndexOutOfBoundsException</h2> <p>The Java Virtual Machine (JVM) throws an ArrayIndexOutOfBoundsException if length of the array in negative, equal to the array size or greater than the array size while traversing the array.</p> <pre> //Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread 'main' java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let's see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){></pre></arr.length;i++)> ArrayIndexOutOfBoundsException
La màquina virtual de Java (JVM) llança una ArrayIndexOutOfBoundsException si la longitud de la matriu és negativa, igual a la mida de la matriu o superior a la mida de la matriu mentre travessa la matriu.
//Java Program to demonstrate the case of //ArrayIndexOutOfBoundsException in a Java Array. public class TestArrayException{ public static void main(String args[]){ int arr[]={50,60,70,80}; for(int i=0;i<=arr.length;i++){ system.out.println(arr[i]); } }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> Exception in thread 'main' java.lang.ArrayIndexOutOfBoundsException: 4 at TestArrayException.main(TestArrayException.java:5) 50 60 70 80 </pre> <hr> <h2>Multidimensional Array in Java</h2> <p>In such case, data is stored in row and column based index (also known as matrix form).</p> <p> <strong>Syntax to Declare Multidimensional Array in Java</strong> </p> <pre> dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[]; </pre> <p> <strong>Example to instantiate Multidimensional Array in Java</strong> </p> <pre> int[][] arr=new int[3][3];//3 row and 3 column </pre> <p> <strong>Example to initialize Multidimensional Array in Java</strong> </p> <pre> arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9; </pre> <h3>Example of Multidimensional Java Array</h3> <p>Let's see the simple example to declare, instantiate, initialize and print the 2Dimensional array.</p> <pre> //Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+\' \'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\' \'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\' \'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\' \'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){></pre></=arr.length;i++){> Matriu multidimensional en Java
En aquest cas, les dades s'emmagatzemen en un índex basat en files i columnes (també conegut com a forma de matriu).
Sintaxi per declarar matriu multidimensional en Java
dataType[][] arrayRefVar; (or) dataType [][]arrayRefVar; (or) dataType arrayRefVar[][]; (or) dataType []arrayRefVar[];
Exemple per crear una instancia de matriu multidimensional en Java
int[][] arr=new int[3][3];//3 row and 3 column
Exemple per inicialitzar la matriu multidimensional en Java
arr[0][0]=1; arr[0][1]=2; arr[0][2]=3; arr[1][0]=4; arr[1][1]=5; arr[1][2]=6; arr[2][0]=7; arr[2][1]=8; arr[2][2]=9;
Exemple de matriu Java multidimensional
Vegem l'exemple senzill per declarar, instanciar, inicialitzar i imprimir la matriu 2Dimensional.
//Java Program to illustrate the use of multidimensional array class Testarray3{ public static void main(String args[]){ //declaring and initializing 2D array int arr[][]={{1,2,3},{2,4,5},{4,4,5}}; //printing 2D array for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" system.out.print(arr[i][j]+\\' \\'); } system.out.println(); }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 1 2 3 2 4 5 4 4 5 </pre> <h2>Jagged Array in Java</h2> <p>If we are creating odd number of columns in a 2D array, it is known as a jagged array. In other words, it is an array of arrays with different number of columns.</p> <pre> //Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\\' \\'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;></pre></3;i++){> Jagged Array a Java
Si estem creant un nombre senar de columnes en una matriu 2D, es coneix com a matriu irregular. En altres paraules, és una matriu de matrius amb un nombre diferent de columnes.
//Java Program to illustrate the jagged array class TestJaggedArray{ public static void main(String[] args){ //declaring a 2D array with odd columns int arr[][] = new int[3][]; arr[0] = new int[3]; arr[1] = new int[4]; arr[2] = new int[2]; //initializing a jagged array int count = 0; for (int i=0; i <arr.length; i++) for(int j="0;" <arr[i].length; j++) arr[i][j]="count++;" printing the data of a jagged array for (int i="0;" <arr.length; i++){ j++){ system.out.print(arr[i][j]+\\' \\'); } system.out.println(); new line < pre> <span> Test it Now </span> <p>Output:</p> <pre> 0 1 2 3 4 5 6 7 8 </pre> <hr> <h2>What is the class name of Java array?</h2> <p>In Java, an array is an object. For array object, a proxy class is created whose name can be obtained by getClass().getName() method on the object.</p> <pre> //Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} </pre> <span> Test it Now </span> <p>Output:</p> <pre> I </pre> <hr> <h2>Copying a Java Array</h2> <p>We can copy an array to another by the arraycopy() method of System class.</p> <p> <strong>Syntax of arraycopy method</strong> </p> <pre> public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length ) </pre> <h3>Example of Copying an Array in Java</h3> <pre> //Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } </pre> <span> Test it Now </span> <p>Output:</p> <pre> caffein </pre> <hr> <h2>Cloning an Array in Java</h2> <p>Since, Java array implements the Cloneable interface, we can create the clone of the Java array. If we create the clone of a single-dimensional array, it creates the deep copy of the Java array. It means, it will copy the actual value. But, if we create the clone of a multidimensional array, it creates the shallow copy of the Java array which means it copies the references.</p> <pre> //Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} </pre> <p>Output:</p> <pre> Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false </pre> <h2>Addition of 2 Matrices in Java</h2> <p>Let's see a simple example that adds two matrices.</p> <pre> //Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){></pre></arr.length;> Quin és el nom de classe de la matriu Java?
A Java, una matriu és un objecte. Per a l'objecte matriu, es crea una classe proxy el nom es pot obtenir mitjançant el mètode getClass().getName() de l'objecte.
//Java Program to get the class name of array in Java class Testarray4{ public static void main(String args[]){ //declaration and initialization of array int arr[]={4,4,5}; //getting the class name of Java array Class c=arr.getClass(); String name=c.getName(); //printing the class name of Java array System.out.println(name); }} Prova-ho ara Sortida:
I
Còpia d'una matriu Java
Podem copiar una matriu a una altra mitjançant el mètode arraycopy() de la classe System.
Sintaxi del mètode arraycopy
public static void arraycopy( Object src, int srcPos,Object dest, int destPos, int length )
Exemple de còpia d'una matriu en Java
//Java Program to copy a source array into a destination array in Java class TestArrayCopyDemo { public static void main(String[] args) { //declaring a source array char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; //declaring a destination array char[] copyTo = new char[7]; //copying array using System.arraycopy() method System.arraycopy(copyFrom, 2, copyTo, 0, 7); //printing the destination array System.out.println(String.valueOf(copyTo)); } } Prova-ho ara Sortida:
configuració del navegador web
caffein
Clonació d'una matriu en Java
Com que, la matriu Java implementa la interfície Cloneable, podem crear el clon de la matriu Java. Si creem el clon d'una matriu unidimensional, es crea la còpia profunda de la matriu Java. Vol dir que copiarà el valor real. Però, si creem el clon d'una matriu multidimensional, crea la còpia poc profunda de la matriu Java, la qual cosa significa que copia les referències.
//Java Program to clone the array class Testarray1{ public static void main(String args[]){ int arr[]={33,3,4,5}; System.out.println('Printing original array:'); for(int i:arr) System.out.println(i); System.out.println('Printing clone of the array:'); int carr[]=arr.clone(); for(int i:carr) System.out.println(i); System.out.println('Are both equal?'); System.out.println(arr==carr); }} Sortida:
Printing original array: 33 3 4 5 Printing clone of the array: 33 3 4 5 Are both equal? false
Addició de 2 matrius en Java
Vegem un exemple senzill que afegeix dues matrius.
//Java Program to demonstrate the addition of two matrices in Java class Testarray5{ public static void main(String args[]){ //creating two matrices int a[][]={{1,3,4},{3,4,5}}; int b[][]={{1,3,4},{3,4,5}}; //creating another matrix to store the sum of two matrices int c[][]=new int[2][3]; //adding and printing addition of 2 matrices for(int i=0;i<2;i++){ for(int j="0;j<3;j++){" c[i][j]="a[i][j]+b[i][j];" system.out.print(c[i][j]+\\' \\'); } system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 2 6 8 6 8 10 </pre> <h2>Multiplication of 2 Matrices in Java</h2> <p>In the case of matrix multiplication, a one-row element of the first matrix is multiplied by all the columns of the second matrix which can be understood by the image given below.</p> <img src="//techcodeview.com/img/java-object-class/39/java-arrays.webp" alt="Matrix Multiplication in Java"> <p>Let's see a simple example to multiply two matrices of 3 rows and 3 columns.</p> <pre> //Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){></pre></2;i++){> Multiplicació de 2 matrius en Java
En el cas de la multiplicació de matrius, un element d'una fila de la primera matriu es multiplica per totes les columnes de la segona matriu que es pot entendre amb la imatge que es mostra a continuació.
Vegem un exemple senzill per multiplicar dues matrius de 3 files i 3 columnes.
//Java Program to multiply two matrices public class MatrixMultiplicationExample{ public static void main(String args[]){ //creating two matrices int a[][]={{1,1,1},{2,2,2},{3,3,3}}; int b[][]={{1,1,1},{2,2,2},{3,3,3}}; //creating another matrix to store the multiplication of two matrices int c[][]=new int[3][3]; //3 rows and 3 columns //multiplying and printing multiplication of 2 matrices for(int i=0;i<3;i++){ for(int j="0;j<3;j++){" c[i][j]="0;" k="0;k<3;k++)" { c[i][j]+="a[i][k]*b[k][j];" } end of loop system.out.print(c[i][j]+\\' \\'); printing matrix element system.out.println(); new line }} < pre> <span> Test it Now </span> <p>Output:</p> <pre> 6 6 6 12 12 12 18 18 18 </pre> <h3>Related Topics</h3> <h2> 1) Java Program to copy all elements of one array into another array </h2> <h2> 2) Java Program to find the frequency of each element in the array </h2> <h2> 3) Java Program to left rotate the elements of an array </h2> <h2> 4) Java Program to print the duplicate elements of an array </h2> <h2> 5) Java Program to print the elements of an array </h2> <h2> 6) Java Program to print the elements of an array in reverse order </h2> <h2> 7) Java Program to print the elements of an array present on even position </h2> <h2> 8) Java Program to print the elements of an array present on odd position </h2> <h2> 9) Java Program to print the largest element in an array </h2> <h2> 10) Java Program to print the smallest element in an array </h2> <h2> 11) Java Program to print the number of elements present in an array </h2> <h2> 12) Java Program to print the sum of all the items of the array </h2> <h2> 13) Java Program to right rotate the elements of an array </h2> <h2> 14) Java Program to sort the elements of an array in ascending order </h2> <h2> 15) Java Program to sort the elements of an array in descending order </h2> <h2>16) Find 3rd Largest Number in an Array </h2> <h2>17) Find 2nd Largest Number in an Array </h2> <h2>18) Find Largest Number in an Array </h2> <h2>19) Find 2nd Smallest Number in an Array </h2> <h2>20) Find Smallest Number in an Array </h2> <h2>21) Remove Duplicate Element in an Array </h2> <h2>22) Add Two Matrices </h2> <h2>23) <a href="/java-program-multiply-two-matrices">Multiply Two Matrices</a> </h2> <h2>24) Print Odd and Even Number from an Array </h2> <h2>25) Transpose matrix </h2> <h2> 26) Java Program to subtract the two matrices </h2> <h2> 27) Java Program to determine whether a given matrix is an identity matrix </h2> <h2> 28) Java Program to determine whether a given matrix is a sparse matrix </h2> <h2> 29) Java Program to determine whether two matrices are equal </h2> <h2> 30) Java Program to display the lower triangular matrix </h2> <h2> 31) Java Program to display the upper triangular matrix </h2> <h2> 32) Java Program to find the frequency of odd & even numbers in the given matrix </h2> <h2> 33) Java Program to find the product of two matrices </h2> <h2> 34) Java Program to find the sum of each row and each column of a matrix </h2> <h2> 35) Java Program to find the transpose of a given matrix </h2></3;i++){>