Regarding regex

[B pandoo]

public class Sting
{
public static void main(String[] args){
String str = "aaaaaaaaabb";
String[] s = str.split("a{3}");
System.out.println(s.length);
}
}

Answer is 4.
pleas explain the output..
what does a{3} represents?

[Barry Gaunt]

Look at the API for java.util.regex - the Pattern class and under Greedy Quantifiers.

[Abdul Rehman]

The regex "a{3}" means the character 'a' exactly 3 times.
To understand the output, you should know how the split() method works. See the API for this method in the java.util.regex.Pattern class.
After that, try playing with the code. Here is a modified version of the code alongwith the output.

public class SplitTest1 {
   public static void main(String...args) {
       String str = "xaaaxaaaxaaabb";
       String[] s = str.split("a{3}");
       System.out.println(s.length);
       for(String x : s)
          System.out.println(x);
   }
}

This gives the output:

4
x
x
x
bb

Think out why we get such an output? Once done, look at your own code. The only change is that the 'x' characters have been omitted in your version. So, think out why the output is 4?

Regards,
Abdul Rehman.