How to define multiple groups in a regular expression | Java Regex | Regex in java

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RegexDemo.java

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

/**
 * Multiple Groups:
 * A regular expression can have multiple groups.
 *
 */
public class RegexDemo
{

    public static void main(String[] args)
    {
        String text = "John writes about this, and John Doe writes about that,"
                + " and John Wayne writes about everything.";

        /*
         * This expression matches the text "John" followed by a
         * space, and then one or more characters.
         *
         * This expression contains a few characters with special
         * meanings in a regular expression. The . means
         * "any character". The + means "one or more times", and
         * relates to the . (any character, one or more times). The ?
         * means "match as small a number of characters as possible".
         */
        String regex = "(John) (.+?) ";

        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(text);

        while (matcher.find())
        {
            System.out.println("found: " + matcher.group(1) + " "
                    + matcher.group(2));
        }

    }

}

Output

found: John writes
found: John Doe
found: John Wayne

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RegexDemo-multiple_group_john.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RegexDemo-multiple_group_john

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/57d5e7f2c5fabff367c40b36a92925e1158e7f5a/BasicJava/RegexDemo-multiple_group_john/?at=master

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