The startsWith () method in Java returns true on an empty String. How?

Possible duplicate:
Why does "abcd" .StartsWith ("") return true?

The following simple Java code just uses the method startsWith().

package startwithdemo;

final public class Main
{    
    public static void main(String[] args)
    {
        System.out.println("My String".startsWith("M"));
        System.out.println("My String".startsWith("My"));
        System.out.println("My String".startsWith(""));
    }
}

It displays truein all cases. The first two cases are obvious, but in the latter case (with an empty string) it returns true. How?