String concatenation and comparison

public class StringTest {

public static void main(String[] args) {

int i = 4;

int j = 5;

System.out.println ("Hello" + i); // will l print Hello4

System.out.println ( i + j) ; // will print 9

String s1 = new String ("pakistan");

String s2 = "pakistan";

if (s1 == s2) {

System.out.println("comparing string using == operator");

}

if (s1.equals( s2) ) {

System.out.println("comparing string using equal method");

}

}

}

On execution of the above program, following output will produce