Java Character isDigit() Method

The isDigit(int codePoint) method of Character class generally determines whether the given character is a digit or not. Generally, a character is considered as a digit if its general category given by getType(codePoint), is DECIMAL_DIGIT_NUMBER.

Syntax

Parameter

The above method requires only one parameter:

a.)The codePoint which is a Unicode character that needs to be tested.

Return Value

The isDigit(int codePoint) method returns a boolean value i.e. true, if the given(or specified) character is a digit. Otherwise, the method returns false.

Example 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.\n");
		}
		else{
		System.out.print("The codePoint \'"+codepoint1+"\' is not a digit.\n");
		}
		if(check2){
		System.out.print("The codePoint \'"+codepoint2+"\' is a digit.\n");
		}
		else{
		System.out.print("The codePoint \'"+codepoint2+"\' is not a digit.\n");
		}
		if(check3){
		System.out.print("The codePoint \'"+codepoint3+"\' is a digit.\n");
		}
		else{
		System.out.print("The codePoint \'"+codepoint3+"\' is not a digit.\n");
		}	
		if(check4){
		System.out.print("The codePoint \'"+codepoint4+"\' is a digit.\n");
		}
		else{
		System.out.print("The codePoint \'"+codepoint4+"\' is not a digit.\n");
		}
		if(check5){
		System.out.print("The codePoint \'"+codepoint5+"\' is a digit.\n");
		}
		else{
		System.out.print("The codePoint \'"+codepoint5+"\' is not a digit.\n");
		}	
	}
}

Test it Now

Output:

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.

Example 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 );
	   }
}

Test it Now

Output:

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

Java Character isDigit() Method

The isDigit(char ch) method of Character class generally determines whether the given character is a digit or not.

Generally, a character is considered as a digit if its general category given by Character.getType(ch), is DECIMAL_DIGIT_NUMBER.

Note: The above method cannot be used to handle the supplementary characters. In order to support all the Unicode characters, including all the supplementary characters, we can use the isdigit(int) method.

Syntax

Parameter

The above method requires only one parameter

a.)The character that needs to be tested.

Return Value

The isDigit(char ch) method returns a boolean value, i.e., true if the given(or specified) character is a digit. Otherwise, the method returns false.

Example 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 );
	   }
	}

Test it Now

Output:

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

Example 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.\n");
		}
		else{
		System.out.print("The character \'"+value1+"\' is not a digit.\n");
		}
   // 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.\n");
			}
		else{
		System.out.print("The character \'"+value2+"\' is not a digit.\n");
	       }
       }
}

Test it Now

Output:

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

Example 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 );
	   }
	}

Test it Now

Output:

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

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