regex

Matcher end with parameter example

In this example we shall show you how to use Matcher.end(int group) API method to get the offset after the last character of the subsequence captured by the given group, during the previous match operation. To use Matcher.end(int group) one should perform the following steps:

  • Compile a String regular expression to a Pattern, using compile(String regex) API method of Pattern.
  • Use an initial String to be matched against the Pattern.
  • Use matcher(CharSequence input) API method of Pattern to create a Matcher that will match the given String input against this pattern.
  • Find the first subsequence of the input sequence that matches the pattern, using find() API method of Matcher.
  • Get the offset after the last character of the subsequence captured by the given group during the previous match operation, with end(int group) API method. Group zero denotes the entire pattern, so the expression m.end(0) is equivalent to m.end().
  • Use end(int group) API method again to get the offset after the last character of the subsequence captured by the specified group during the previous match operation, setting the int group parameter to 1.
  • Find the next subsequence of the input sequence that matches the pattern, and again get the offset after the last character of the subsequence captured by the entire pattern and by the group 1,

as described in the code snippet below.

package com.javacodegeeks.snippets.core;

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

public class MatcherEnd {

    public static void main(String args[]) {

  

  Pattern pattern = Pattern.compile("B(on)d");


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


  String mHelper[] = {"

   ^", "

  ^",


"



   ^", "



  ^"};

  Matcher m = pattern.matcher(str);


  m.find();

  int end = m.end(0);

  System.out.println(str);

  System.out.println(mHelper[0] + end);


  int next = m.end(1);

  System.out.println(str);

  System.out.println(mHelper[1] + next);


  m.find();

  end = m.end(0);

  System.out.println(str);

  System.out.println(mHelper[2] + end);


  next = m.end(1);

  System.out.println(str);

  System.out.println(mHelper[3] + next);
    
    }
}

Output:

My name is Bond. James Bond.


   ^15
My name is Bond. James Bond.


  ^14
My name is Bond. James Bond.




   ^27
My name is Bond. James Bond.




  ^26

 
This was an example of Matcher.end(int group) API method in Java.

Ilias Tsagklis

Ilias is a software developer turned online entrepreneur. He is co-founder and Executive Editor at Java Code Geeks.
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