Java PatternSyntaxException Class getIndex() Method with Examples Last Updated : 02 Feb, 2022 Suggest changes Share Like Article Like Report Java PatternSyntaxException Class is defined under the java.util.regex package and it depicts unchecked exception that signifies syntax error in a regular expression pattern. This class can be declared using the below syntax, public class PatternSyntaxException extends IllegalArgumentExceptionPatternSyntaxException::getIndex() This method is used to retrieve the index of the error which is thrown as an exception. The syntax is given below, Syntax: public int getIndex() Returns: It returns a non-negative integer: The index in the pattern of the error is -1 if the index cannot be retrieved Example 1: In this example, the error is at the index 0 in the pattern. This is because of the unclosed character. Java // Java program to illustrate the working of getIndex() method import java.io.*; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; class GFG { private static String regularExpression = "["; private static String input = "GeeksforGeeks " + "is a learning platform."; private static String replace = "Hi"; public static void main (String[] args) { try{ // Compile the pattern Pattern pattern = Pattern.compile(regularExpression); // To get a matcher object Matcher matcher = pattern.matcher(input); input = matcher.replaceAll(replace); } catch(PatternSyntaxException e){ // Print the index in the error of the pattern System.out.println("Index: "+ e.getIndex()); System.out.println("Message: "+ e.getMessage()); } } } OutputIndex: 0 Message: Unclosed character class near index 0 [ ^ Example 2: In this example, getIndex() method returns -1. This is because of illegal repetition the index cannot be retrieved. Java // Java program to illustrate the working of getIndex() method import java.io.*; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; class GFG { // Declaring a string variable to store the regular expression private static String regularExpression = "{"; private static String input = "GeeksforGeeks " + "is a learning platform."; private static String replace = "Hello"; public static void main (String[] args) { try{ // Compile the pattern Pattern pattern = Pattern.compile(regularExpression); // To get a matcher object Matcher matcher = pattern.matcher(input); input = matcher.replaceAll(replace); } catch(PatternSyntaxException e){ // Print the index in the error of the pattern System.out.println("Index: "+ e.getIndex()); System.out.println("Message: "+ e.getMessage()); } } } OutputIndex: -1 Message: Illegal repetition { Advertise with us Next Article Java PatternSyntaxException Class getIndex() Method with Examples B bhuwanesh Follow Similar Reads Java PatternSyntaxException Class getMessage() Method with Examples Java provides Regular Expressions or Regex (in short) API for creating string patterns to search, manipulate, and edit a string in Java. This class is defined under the java.util.regex package and it focuses upon the unchecked exception that signifies syntax error in a regular expression pattern. Th 4 min read Java PatternSyntaxException Class getPattern() Method with Examples Java provides Regular Expressions or Regex (in short) API for creating string patterns to search, manipulate, and edit a string in Java. This class is defined under the java.util.regex package and it focuses upon the unchecked exception that signifies syntax error in a regular expression pattern. Th 4 min read Java PatternSyntaxException Class getDescription() Method with Examples Java PatternSyntaxException Class is defined under the java.util.regex package and it focuses upon the unchecked exception that signifies syntax error in a regular expression pattern. This class can be declared using the below syntax. Syntax: public class PatternSyntaxException extends IllegalArgume 4 min read ParsePosition getIndex() method in Java with Example The getIndex() method of java.text.ParsePosition class is used to retrieve the current parse position of this ParsePositon object . Syntax: public int getIndex() Parameter: This method does not accepts any argument as parameter. Return Value: This method returns the current parse position of this pa 2 min read ParsePosition getErrorIndex() method in Java with Example The getErrorIndex() method of java.text.ParsePosition class is used to retrieve the index at which parse error may occur. Syntax: public int getErrorIndex() Parameter: This method does not accepts any argument as a parameter. Return Value: This method returns the index at which parse error may occur 2 min read Article Tags : Java Java-Functions Java-PatternSyntaxException-Class Practice Tags : Java Like