String issue

[Dana Ucaed]

Hello,

package equals2;

/**
 *
 * @author andad
 */
public class Equals2 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        String s1 = "Manish";
	String s2 = s1;
	s1 = null;
        System.out.println(s2);
	System.out.println(s2.equals(s1));
    }
    
}

Why s2 is not null, because s1 becomes null, s1 remains "Manish"?

I am very confused.

Can you help me?

[Liutauras Vilda]

Think you have a dog, which has two laces which are secured on his neck/head (in your case it is object "Manish"). Now you cut one of the lace, what happens with other? It still on dog's neck. That's probably confusing.

s1 isn't an object, but rather a reference variable which refers to a string object "Manish". Now that you let s2 variable to refer to the same object, "Manish" now has two reference variables referencing to him. So, if you eliminate s1, s1 is no longer pointing to "Manish", but hey, s2 still does. Similarly as in an above example I crossed off.

[Roel De Nijs]

Dana Ucaed wrote:Why s2 is not null, because s1 becomes null, s1 remains "Manish"?

You should definitely read this excellent article.

[Mark Spencers]

s2 is not null because at this line

String s2 = s1;

you made it refer to object

"Manish"

. And with line

s1=null

you made s1 refer to null in memory