Comments on: The ‘final’ keyword in Java

By: gitanjalli

gitanjalli — Sat, 21 Jan 2012 06:05:27 +0000

what do u mean by final keyword?
what is the use of vector class?
plz clearify it

By: Jan-Hendrik van Heusden

Jan-Hendrik van Heusden — Mon, 10 Oct 2011 08:52:26 +0000

This explanation is clear and correct, yet I miss a really important point, which me be very naughty to beginners.
That’s the use of final for variables (either local or instance variables) that point to Objects.

// Declare final
final MyClass myFinalClassVar = new MyClass();
// other
MyClass myOtherClassVar = new MyClass();

// Can not assign an other value…
myFinalClassVar = myOtherClassVar; // illegal

// But I *can* change properties of the underlying object:
myFinalClassVar.changeSomethingOfIt(newValue);
// OK, so the variable can not reassigned, but the underlying objects’s property are still mutable!

By: Sumant

Sumant — Wed, 06 Jul 2011 07:14:04 +0000

Thanks for posting this valueable article.

By: Nischal Shetty

Nischal Shetty — Wed, 29 Sep 2010 06:14:21 +0000

@pravin In simple words, when you create 2 strings with same value ,

String s = “Hi”;
String t – “Hi”;

Internally its just a single “Hi” that is present. Now if Strings were not immutable, then if you did a

s.concat(“Bye”);

This would change the value for variable “t” as well. Hope you got the point.

It is for the very same reason why a simple (s==t) would return true in the case of String but not for other objects.

By: pravin

pravin — Wed, 29 Sep 2010 06:05:19 +0000

string objects are immutable o.k .what is the reason to make a string object as immutable?
plz clarify my doubt.

By: Nischal Shetty

Nischal Shetty — Wed, 18 Feb 2009 15:35:29 +0000

@lakshmi

Yeah, very true Thanks for pointing that out. My article holds good for instance variables that are final.

Class variables which are final are the ones that can be only initialized inside the constructor.

By: lakshmi

lakshmi — Wed, 18 Feb 2009 06:26:26 +0000

Variable which is marked final and not initialized can be initialized only once in constructor, not anywhere else.
If the final variable is static, then it can be initialized only once in static initialization blocks.

By: techtamasha.com » Blog Archive » Difference between String and StringBuffer/StringBuilder in Java

Tue, 24 Jun 2008 11:34:59 +0000

[...] Link: Have doubts about the ‘final’ keyword? check out my post – Click Here! [...]