Character.isIdentifierIgnorable() in Java with Examples Last Updated : 06 Dec, 2018 Improve Improve Like Article Like Save Share Report The java.lang.Character.isIdentifierIgnorable(char ch) is an inbuilt method in java that determines if the specified character 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 Syntax: public static boolean isIdentifierIgnorable(char ch) Parameters: The parameter ch is of character datatype and refers to the character that is 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. Below programs illustrate the Character.isIdentifierIgnorable(char ch) method: Program 1: // Java program to illustrate // Character.isIdentifierIgnorable(char ch) method import java.lang.*; public class gfg { public static void main(String[] args) { // Creates 2 character primitives c1, c2 and assigning values char c1='\u0000', c2= '9'; // Assigns isIdentifierIgnorable results of // c1, c2 to boolean primitives boolean bool1 = Character.isIdentifierIgnorable(c1); boolean bool2 = Character.isIdentifierIgnorable(c2); String str1 = "c1 is an ignorable control character is " + bool1; String str2 = "c2 is an ignorable control character is " + bool2; System.out.println( str1 ); System.out.println( str2 ); } } Output: c1 is an ignorable control character is true c2 is an ignorable control character is false Program 2: import java.lang.*; public class gfg { public static void main(String[] args) { // Create 2 character primitives c1, c2 and assigning values char c1='\u000E', c2= '8'; // Assigns isIdentifierIgnorable results of // c1, c2 to boolean primitives boolean bool1 = Character.isIdentifierIgnorable(c1); boolean bool2 = Character.isIdentifierIgnorable(c2); String str1 = "c1 is an ignorable control character is " + bool1; String str2 = "c2 is an ignorable control character is " + bool2; System.out.println( str1 ); System.out.println( str2 ); } } Output: c1 is an ignorable control character is true c2 is an ignorable control character is false The java.lang.Character.isIdentifierIgnorable(int codePoint) is similar to the previous method in all manner. Syntax: public static boolean isIdentifierIgnorable(int codePoint) Parameter: The function accepts a single parameter codePoint of integer datatype which specifies the character (Unicode code point) that is 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. Below program illustrates the Character.isIdentifierIgnorable(int codepoint) method: Program 1: // Java program to demonstrate // the Character.isIdentifierIgnorable(int codepoint) method import java.lang.*; public class gfg { public static void main(String[] args) { // Integer primitives c1, c2 int c1 = 0x019f, c2 = 0x1abc; // Assign isIdentifierIgnorable results of cp1, cp2 // to boolean primitives bool1, bool2 boolean bool1 = Character.isIdentifierIgnorable(c1); boolean bool2 = Character.isIdentifierIgnorable(c2); // Print bool1, bool2 values System.out.println( "c1 is an ignorable control character?"+ " ans is "+bool1); System.out.println( "c2 is an ignorable control character?"+ " ans is "+bool2); } } Output: c1 is an ignorable control character? ans is false c2 is an ignorable control character? ans is false Program 2: // Java program to demonstrate // the Character.isIdentifierIgnorable(int codepoint) method import java.lang.*; public class gfg { public static void main(String[] args) { // Integer primitives c1, c2 int c1 = 0x119f, c2 = 0x0abc; // Assign isIdentifierIgnorable results of cp1, cp2 // to boolean primitives bool1, bool2 boolean bool1 = Character.isIdentifierIgnorable(c1); boolean bool2 = Character.isIdentifierIgnorable(c2); // Print bool1, bool2 values System.out.println( "c1 is an ignorable control character?"+ " ans is "+bool1); System.out.println( "c2 is an ignorable control character?"+ " ans is "+bool2); } } Output: c1 is an ignorable control character? ans is false c2 is an ignorable control character? ans is false Reference: https://docs.oracle.com/javase/7/docs/api/java/lang/Character.html#isIdentifierIgnorable(char) Like Article Suggest improvement Next Character.isJavaIdentifierPart() Method in Java with Examples Share your thoughts in the comments Add Your Comment Please Login to comment...