MatchResult groupCount() method in Java with Examples

The groupCount() method of MatchResult Interface is used to get the number of capturing groups in this matcher’s pattern. This method returns an integer value which is the number of groups found while matching this matcher.
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 MatchResult.groupCount() method:
Example 1:

Java

// 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 Geeks for For Geeks Geek";

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

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

Output:

1

Example 2:

Java

// 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
            = "FGF GF FG FGF";

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

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

Output:

0

Reference: https://docs.oracle.com/javase/9/docs/api/java/util/regex/Matcher.html#groupCount–