Immutability of Strings in Java

Question

Consider the following example.

String str = new String();

str  = \"Hello\";
System.out.println(str);  //Prints Hello

str = \"Help!\";
System.out.println(s         


        

Answer 1

Immutability implies that the value of an instantiated object cannot change, you can never turn "Hello" into "Help!".

The variable str is a reference to an object, when you assign a new value to str you aren't changing the value of the object it references, you are referencing a different object.