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

The object that str references can change, but the actual String objects themselves cannot.

The String objects containing the string "Hello" and "Help!" cannot change their values, hence they are immutable.

The immutability of String objects does not mean that the references pointing to the object cannot change.

One way that one can prevent the str reference from changing is to declare it as final:

final String STR = "Hello";

Now, trying to assign another String to STR will cause a compile error.