java.util.regex.Matcher.region() Method

Description

The java.util.regex.Matcher.region(int start, int end) method sets the limits of this matcher's region. The region is the part of the input sequence that will be searched to find a match. Invoking this method resets the matcher, and then sets the region to start at the index specified by the start parameter and end at the index specified by the end parameter.

Declaration

Following is the declaration for java.util.regex.Matcher.region(int start, int end) method.

public Matcher region(int start, int end)

Parameters

• start − The index to start searching at (inclusive).

• end − The index to end searching at (exclusive).

Return Value

this matcher.

Example

The following example shows the usage of java.util.regex.Matcher.region(int start, int end) method.

package com.tutorialspoint;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MatcherDemo {
   private static String REGEX = "(a*b)(foo)";
   private static String INPUT = "aabfooaabfooabfoob";
   private static String REPLACE = "-";
   
   public static void main(String[] args) {
      Pattern pattern = Pattern.compile(REGEX);
      
      // get a matcher object
      Matcher matcher = pattern.matcher(INPUT);
      matcher = matcher.region(0, 10);
      
      while(matcher.find()) {
         //Prints the offset after the last character matched.
         System.out.println("First Capturing Group, (a*b) Match String end(): "+matcher.end());    
      }     
   }
}

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

First Capturing Group, (a*b) Match String end(): 6