String Concatenation in Java

public class ConcatExample

{  

    public static void main(String args[])

    {  

        String s1="Hello Sukhvir";//Declaration of First String  

        s1.concat("How are you?");//Concatenation is there but not saved in s1  

        System.out.println(s1);//Printing of only First String  

        s1=s1.concat(" Java is a Pure Object Oriented Language");

        //Hello Sukhvir and this Line will be the output

        //as it is stored in s1

        System.out.println(s1);  

    }

}