Matcher: start()

int start(): Returns the start index of the previous match.


/*
 * Output:
java found at index 4
 * */

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

public class MainClass {
  public static void main(String args[]) {
    Pattern pat = Pattern.compile("java");
    Matcher mat = pat.matcher("www.java2s.com 1 2 3 j a v a 2 s.c o m");

    while (mat.find()) {
      System.out.println("java found at index " + mat.start());
    }
  }
}