Java.lang.Character.isIdentifierIgnorable() Method



The java.lang.Character.isIdentifierIgnorable(int codePoint) determines if the specified character (Unicode code point) should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

The following Unicode characters are ignorable in a Java identifier or a Unicode identifier −

  • 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


Following is the declaration for java.lang.Character.isIdentifierIgnorable() method

public static boolean isIdentifierIgnorable(int codePoint)


codePoint − the character (Unicode code point) to be tested

Return Value

This method returns true if the character is an ignorable control character that may be part of a Java or Unicode identifier, false otherwise.




The following example shows the usage of lang.Character.isIdentifierIgnorable() method.

package com.tutorialspoint;

import java.lang.*;

public class CharacterDemo {

   public static void main(String[] args) {

      // create 2 int primitives cp1, cp2
      int cp1, cp2;

      // assign values to cp1, cp2
      cp1 = 0x008f;
      cp2 = 0x0abc;

      // create 2 boolean primitives b1, b2
      boolean b1, b2;

      // assign isIdentifierIgnorable results of cp1, cp2 to b1, b2
      b1 = Character.isIdentifierIgnorable(cp1);
      b2 = Character.isIdentifierIgnorable(cp2);

      String str1 = "cp1 is an ignorable control character is "+b1;
      String str2 = "cp2 is an ignorable control character is "+b2;

      // print b1, b2 values
      System.out.println( str1 );
      System.out.println( str2 );

Let us compile and run the above program, this will produce the following result −

cp1 is an ignorable control character is true
cp2 is an ignorable control character is false