Two different variables with same String value are referred to same memory address

Question

I know that Strings are immutable. But I have a doubt in below code:

class StringTest {
   String s1 = "Joe";
   String s2 = "Joe";
   System.out.println(s1 == s2);
}

== checks whether both are referred to same memory address or not (if I am not wrong). If so, even the two strings are assigned to two different variables, why the output says both are referred to same memory address.

score 1 · Answer 1 · answered Mar 09 '15 at 15:08

Java uses an intern pool for performance, and so those two variables refer to the same String. You can use new to get a new one, like

class StringTest {
    public static void main(String[] args) {
        String s1 = "Joe";
        String s2 = new String("Joe");
        System.out.println(s1 == s2);
    }
}

Two different variables with same String value are referred to same memory address

1 Answers1