Java tutorial
public class Main { public static void main(String[] args) throws Exception { String s1 = "java2s"; String s2 = "java2s.com"; String s3 = "Java2s.com"; // returns the HashCode int ret1 = System.identityHashCode(s1); System.out.println(ret1); // returns different HashCode for same filename int ret2 = System.identityHashCode(s2); System.out.println(ret2); // returns the HashCode int ret3 = System.identityHashCode(s3); System.out.println(ret3); } }