One cannot change the String type value assigned to a variable without changing the reference. There are several reasons why JVM authors decided to do that:
- All String literals are stored in the same common memory area, called string pool. Before a new String literal is stored, the JVM checks whether such a literal is already stored there. If such an object exists already, a new object is not created and the reference to the existing object is returned as the reference to a new object. The following code demonstrates this situation:
System.out.println("s1" == "s1"); System.out.println("s1" == "s2"); String s1 = "s1"; System.out.println(s1 == "s1"); System.out.println(s1 == "s2"); String s2 = "s1"; System.out.println(s1 ...
