Matcher groupCount() method in Java with Examples

The groupCount() method of Matcher Class is used to get the number of capturing groups in this matcher’s pattern.

Syntax:

public int groupCount()

Parameters: This method do not takes any parameter.

Return Value: This method returns the number of capturing groups in this matcher’s pattern.

Below examples illustrate the Matcher.groupCount() method:

Example 1:

// Java code to illustrate groupCount() method

import java.util.regex.*;

public class GFG {
    public static void main(String[] args)
    {

        // Get the regex to be checked
        String regex = "Geeks";

        // Create a pattern from regex
        Pattern pattern
            = Pattern.compile(regex);

        // Get the String to be matched
        String stringToBeMatched
            = "GeeksForGeeks";

        // Create a matcher for the input String
        Matcher matcher
            = pattern
                  .matcher(stringToBeMatched);

        // Get the number of capturing groups
        // using groupCount() method
        System.out.println(matcher.groupCount());
    }
}

Output:

0

Example 2:

// Java code to illustrate groupCount() method

import java.util.regex.*;

public class GFG {
    public static void main(String[] args)
    {

        // Get the regex to be checked
        String regex = "GFG";

        // Create a pattern from regex
        Pattern pattern
            = Pattern.compile(regex);

        // Get the String to be matched
        String stringToBeMatched
            = "GFGFGFGFGFGFGFGFGFG";

        // Create a matcher for the input String
        Matcher matcher
            = pattern
                  .matcher(stringToBeMatched);

        // Get the number of capturing groups
        // using groupCount() method
        System.out.println(matcher.groupCount());
    }
}

Output:

0

Reference: Oracle Doc