?? (string1 == string2) ??

Question

Can someone please explain the rules here
public class A {
public static void main(String args[]) {
String s1 = "abc";
String s2 = "abc";
System.out.println(s1 == s2);
String s3 = new String("abc");
System.out.println(s1 == s3);
I was expecting "false" "false" but the first was is true - WHY?

Answer 1

As joeldi pointed out, if they are both pointing to (referencing) the same bit of memory, they are equal (==), like so:
String s1 = "abc";
String s2 = s1;
System.out.println(s1==s2);This will return true.
Doing this isn't so different.
String s1 = "abc";
String s2 = "abc";Because s1 and s2 are being given exactly the same value, the compiler is smart enough to save memory and point them both at the same "abc" literal (is this what they mean by interning?). And since Strings are immutable (can't be changed) it doesn't matter in the slightest, since s1 can't possibly upset the data in s2.
Cheers,
Radish21