String and Final

[Bhagat Singh Rawat]

Hi Rancher,

Can someone explain the below mentioned scenarios in the detail?

Scenrio-1

String name = "Test"
name = name + "Java";           // It works

Scenario-2

final String name = "Test"
name = name + "Java";    //compilation error "The final field String can't be assigned"

If String class is final class then why do we need to create explicitly a final String Instance for CONSTANT variables?

Thanks in advance.

[Rob Spoor]

There is a difference between a class being final and a variable being final.

Final for a class means that it can't be subclassed. Nothing more, nothing less.
Final for a variable (local, instance field, static field) means that it can only can have its value set once - and never again. A final parameter is similar - it can only be assigned from the method call.


In your example, you first assign "Test" to the final variable name. That means that name can never get a new value, and that's just what you're trying to do afterwards.