Matcher groupCount example

In this example we shall show you how to use Matcher.groupCount() API method to get the number of capturing groups in a Matcher‘s pattern. To get the number of capturing groups in a matcher’s pattern one should perform the following steps:

  • 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 groupCount() API method of Matcher to get the number of capturing groups in this matcher’s pattern,

as described in the code snippet below.

package com.javacodegeeks.snippets.core;

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

public class MatcherGroupCount {
  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);

    int numOfGroups = m.groupCount();
    System.out.println("number Of Groups =" + numOfGroups);



number Of Groups : 1

This was an example of Matcher.groupCount() 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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