Checking if strings are equal in java using ==

when i execute the code below, the output is
"false"

String string1
            = new String("ABC"); 
String string2= new String("ABC");
            
System.out.println(string1==string2);
            

However the output
when I don't use the string class's constructor is
"true"

String
            string1;
String
            string2;

string1="ABC";
string2=
            "ABC";
System.out.println(string1==string2);
            

I get that its better
to use the .equals() methods but why the difference in output?

Answer

Always use equals since
== doesn't always work. Even though objects are the same in
memory it may be stored in different places, and == checks for
objects identity and not equality.