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);
}
}
Output:
number Of Groups : 1
This was an example of Matcher.groupCount() API method in Java.
