Regex question

[Dinesh Tahiliani]

import java.util.regex.*;
class Regex2 {
public static void main(String[] args) {
Pattern p = Pattern.compile(args[0]);
Matcher m = p.matcher(args[1]);
boolean b = false;
while(b = m.find()) {
System.out.print(m.start() + m.group());
}
}
}

Answer is --01234456

Can someone expalin me the use of group?

[marc weber]

See our SCJP FAQ: Could someone explain the Regex2 class from K&B's Java 5 Study Guide?