This is an example of how to use Matcher.group(int group) API method to get the input subsequence captured by the given group during the previous match operation. Grouping with a Matcher implies that you should:

• Compile a String regular expression to a Pattern, using compile(String regex) API method of Pattern.
• Use matcher(CharSequence input) API method of Pattern to create a Matcher that will match the given String input against this pattern.
• Use find() API method of Matcher to get the matches of the input with the pattern.
• Use group(int group) API method to get the input subsequence captured by the given group during the previous match operation.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;

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

public class MatcherGroupExample {

    public static void main(String args[]) {

  Pattern pattern = Pattern.compile("B(ond)");


  String str = "My name is Bond. James Bond.";


  Matcher m = pattern.matcher(str);


  m.find();

  String group_0 = m.group(0);

  String group_1 = m.group(1);

  System.out.println("Group 0 " + group_0);

  System.out.println("Group 1 " + group_1);

  System.out.println(str);


  m.find();

  group_0 = m.group(0);

  group_1 = m.group(1);

  System.out.println("Group 0 " + group_0);

  System.out.println("Group 1 " + group_1);

  System.out.println(str);
    }
}

Output:

Group 0 Bond
Group 1 ond
My name is Bond. James Bond.
Group 0 Bond
Group 1 ond
My name is Bond. James Bond.

 
This was an example of how to use Matcher.group(int group) API method in Java.