Question

How do you show all the matches?For example I have one String “Hello world and how are you a”.
Here I have to get all the positions where letter ‘a’ resides.For that I wrote one sample java program. But here only start() and end() methods are available for matcher. How do I get the middle results? Please explain me..

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

public class RegexTestStrings {


 public static void main( String args[] ){


      String line = "Hello world and how are you a";
      String pattern = "[a]";      
      Pattern r = Pattern.compile(pattern);     
      Matcher m = r.matcher(line);
              if (m.find( )) {
        System.out.println(m.start());          
        System.out.println(m.end());


      } else {
         System.out.println("No result foud");
      }
   }
}

Answer 1

You can call matcher.find() more than one time, and it will return the next occurence. So just replace your if with a while and use some boolean flag matchesFound set to true inside the while block in order to be able to print the message if there was no match.