El mètode isDigit(int codePoint) de la classe Character determina generalment si el caràcter donat és un dígit o no. En general, un caràcter es considera un dígit si la seva categoria general donada per getType(codePoint) és DECIMAL_DIGIT_NUMBER.

Sintaxi

 public static boolean isDigit(int codePoint) 

Paràmetre

El mètode anterior només requereix un paràmetre:

convertir booleà en cadena

a.) El codePoint que és un caràcter Unicode que cal provar.

Valor de retorn

El mètode isDigit(int codePoint) retorna un valor booleà, és a dir, true, si el caràcter donat (o especificat) és un dígit. En cas contrari, el mètode retorna false.

Exemple 1

 public class JavaCharacaterisDigitintcodePointExample1 { public static void main(String[] args) { // Initialize the codePoints. int codepoint1 = 55; int codepoint2 = 32; int codepoint3 = 121; int codepoint4 = 49; int codepoint5 = 200; // Check whether a particular codePoint is a digit or not. boolean check1 = Character.isDigit(codepoint1); boolean check2 = Character.isDigit(codepoint2); boolean check3 = Character.isDigit(codepoint3); boolean check4 = Character.isDigit(codepoint4); boolean check5 = Character.isDigit(codepoint5); // Print the result. if(check1){ System.out.print('The codePoint ''+codepoint1+'' is a digit.
'); } else{ System.out.print('The codePoint ''+codepoint1+'' is not a digit.
'); } if(check2){ System.out.print('The codePoint ''+codepoint2+'' is a digit.
'); } else{ System.out.print('The codePoint ''+codepoint2+'' is not a digit.
'); } if(check3){ System.out.print('The codePoint ''+codepoint3+'' is a digit.
'); } else{ System.out.print('The codePoint ''+codepoint3+'' is not a digit.
'); } if(check4){ System.out.print('The codePoint ''+codepoint4+'' is a digit.
'); } else{ System.out.print('The codePoint ''+codepoint4+'' is not a digit.
'); } if(check5){ System.out.print('The codePoint ''+codepoint5+'' is a digit.
'); } else{ System.out.print('The codePoint ''+codepoint5+'' is not a digit.
'); } } } 

Sortida:

 The codePoint '55' is a digit. The codePoint '32' is not a digit. The codePoint '121' is not a digit. The codePoint '49' is a digit. The codePoint '200' is not a digit. 

Exemple 2

 public class JavaCharacaterisDigitintcodePointExample2 { public static void main(String[] args) { // Create four int primitives obj1, obj2, obj3 and obj4. int obj1, obj2, obj3, obj4; // Assign the values to obj1, obj2, obj3 and obj4. obj1 = 0x06f8; obj2 = 0x0432; obj3 = 0x50; obj4 = 0x0c12; // Create four boolean primitives b1, b2, b3 and b4. boolean b1, b2, b3, b4; // Assign the isDigit method b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); b4 = Character.isDigit(obj4); String str1 = 'The first object represents a digit : ' + b1; String str2 = 'The first object represents a digit : ' + b2; String str3 = 'The first object represents a digit : ' + b3; String str4 = 'The first object represents a digit : ' + b4; // Print the values of b1, b2, b3 and b4. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); System.out.println( str4 ); } } 

Sortida:

identificadors vàlids a Java

 The first object represents a digit : true The first object represents a digit : false The first object represents a digit : false The first object represents a digit : false 

El mètode isDigit(char ch) de la classe Character determina generalment si el caràcter donat és un dígit o no.

En general, un caràcter es considera un dígit si la seva categoria general donada per Character.getType(ch), és DECIMAL_DIGIT_NUMBER.

Nota: el mètode anterior no es pot utilitzar per gestionar els caràcters addicionals. Per donar suport a tots els caràcters Unicode, inclosos tots els caràcters suplementaris, podem utilitzar el mètode isdigit(int).

Sintaxi

 public static boolean isDefined(char ch) 

Paràmetre

El mètode anterior només requereix un paràmetre

Neena Gupta

Valor de retorn

El mètode isDigit(char ch) retorna un valor booleà, és a dir, cert si el caràcter donat (o especificat) és un dígit. En cas contrari, el mètode retorna false.

Exemple 3

 public class JavaCharacterisDigitExample3 { public static void main(String[] args) { // Create three char primitives: obj1, obj2, and obj3. char obj1, obj2, obj3; // Assign the values to obj1, obj2 and obj3 respectively. obj1 = ' '; obj2 = '4'; obj3 = '8'; // Create three boolean primitives b1, b2 and b3. boolean b1, b2,b3; //Assign isDigit results of obj1, obj2 and obj3 to b1, b2, and b3 respectively. b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); String str1 = 'The digit '' + obj1 +'' is:'+b1; String str2 = 'The digit '' + obj2 +'' is:'+b2; String str3 = 'The digit '' + obj3 +'' is:'+b3; // Print the values of b1, b2 and b3. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); } } 

Sortida:

 The digit ' ' is:false The digit '4' is:true The digit '8' is:true 

Exemple 4

 import java.util.Scanner; public class JavaCharacterisDigitExample4 { public static void main(String[] args) { // Ask the user to enter the first character. System.out.print('Enter the first character:'); // Use scanner to get the user input. Scanner s1 = new Scanner(System.in); char value1 = s1.nextLine().toCharArray()[0]; // Check whether the input is digit or not. boolean check1 = Character.isDigit(value1); // Print the result if(check1){ System.out.print('The character ''+value1+'' is a digit.
'); } else{ System.out.print('The character ''+value1+'' is not a digit.
'); } // Ask the user to enter the second character. System.out.print('Enter the first character:'); // Use scanner to get the user input. Scanner s2 = new Scanner(System.in); char value2 = s2.nextLine().toCharArray()[0]; // Check whether the input is digit or not. boolean check2 = Character.isDigit(value2); // Print the result. if(check2){ System.out.print('The character ''+value2+'' is a digit.
'); } else{ System.out.print('The character ''+value2+'' is not a digit.
'); } } } 

Sortida:

 Enter the first character: & The character '&' is not a digit. Enter the first character: 3 The character '3' is a digit. 

Exemple 5

 public class JavaCharacterisDigitExample5 { public static void main(String[] args) { // Create four char primitives: obj1, obj2, obj3 and obj4. char obj1, obj2, obj3, obj4; // Assign the values to obj1, obj2, obj3 and obj4 respectively. obj1 = 'A'; obj2 = '3'; obj3 = 'b'; obj4 = '6'; // Create four boolean primitives b1, b2, b3, and b4. boolean b1, b2,b3,b4; // Assign isDigit results of obj1, obj2, obj3, and obj4 to b1, b2 and b3 respectively. b1 = Character.isDigit(obj1); b2 = Character.isDigit(obj2); b3 = Character.isDigit(obj3); b4 = Character.isDigit(obj4); String str1 = 'The digit '' + obj1 +'' is:'+b1; String str2 = 'The digit '' + obj2 +'' is:'+b2; String str3 = 'The digit '' + obj3 +'' is:'+b3; String str4 = 'The digit '' + obj4 +'' is:'+b4; // Print the values of b1, b2, b3 and b4. System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); System.out.println( str4 ); } } 

Sortida:

 The digit 'A' is:false The digit '3' is:true The digit 'b' is:false The digit '6' is:true