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Java Character isIdentifierIgnorable(char ch) Method

Java isIdentifierIgnorable(char ch) method is a part of Character class. This method is used to check whether the specified character can be considered as an ignorable character in Java or a Unicode identifier or not.

The characters which are considered as ignorable characters or Unicode identifier are:

  • ISO control characters that are not whitespace.
    • '\u0000' through '\u0008'
    • '\u000E' through '\u001B'
    • '\u007F' through '\u009F'
  • all characters that have the FORMAT general category value.


public static boolean isIdentifierIgnorable(char ch) 


The parameter passed is the character to be checked for the ignorable character.


Returns the boolean value true if the specified character is an ignorable character else return false.

Example 1:

Here, the characters are checked whether they are ignorable characters or not.

public class StudyTonight
	public static void main(String[] args)
		char ch1 = 'g';  
		char ch2 = 'D';  
		char ch3 = '@';  
		char ch4  = 'e';   
		char ch5  = '8';  

		boolean b1 = Character.isIdentifierIgnorable(ch1);  
		boolean b2 = Character.isIdentifierIgnorable(ch2);  
		boolean b3 = Character.isIdentifierIgnorable(ch3);  
		boolean b4 = Character.isIdentifierIgnorable(ch4);  
		boolean b5 = Character.isIdentifierIgnorable(ch5);  

		System.out.println(ch1 +" is a ignorable?: "+b1);  
		System.out.println(ch2 +" is a ignorable?: "+b2);  
		System.out.println(ch3 +" is a ignorable?: "+b3);  
		System.out.println(ch4 +" is a ignorable?: "+b4);  
		System.out.println(ch5 +" is a ignorable?: "+b5);  

g is a ignorable?: false
D is a ignorable?: false
@ is a ignorable?: false
e is a ignorable? : false
8 is a ignorable?: false

Example 2:

Here is a user-defined example where anyone using this code can put a value of his choice and get the equivalent output.

import java.util.Scanner; 
public class StudyTonight
	public static void main(String[] args)
			System.out.print("Enter the character: ");  
			Scanner sc = new Scanner(;         
			char ch =;  
			boolean b = Character.isIdentifierIgnorable(ch);
			System.out.println(ch + " is a ignorable? : "+b);
		catch(Exception e)
			System.out.println("Invalid Input!!");

Enter the character: t
t is a ignorable? : false
Enter the character: 2
2 is a ignorable? : false

Live Example:

Here, you can test the live code example. You can execute the example for different values, even can edit and write your examples to test the Java code.

About the author:
A Computer Science and Engineering Graduate(2016-2020) from JSSATE Noida. JAVA is Love. Sincerely Followed Sachin Tendulkar as a child, M S Dhoni as a teenager, and Virat Kohli as an adult.