Oct 11, 2014

Types of Final Variable in Java

Final Variable

Before knowing types of final variable you should know What is a Final Variable? Final variable is a variable which  is declared using final keyword before it. For example,

Class Tst
   int final var1 = 10; // var1 is declared as final variable...

There are two very important related to Final Variables that are-

1. Final Variable's value never changes.

2. Final variable must be declared during declaration time.

Now, we will discuss about Types of Final variable.
There are following types of final variables-

1. Final Instance Variable
2. Final Static Variable
3. Final Local Variable
4. Final Block Level Variable
5. Final Parameterized Variable

1. Final Instance Variable -  Those variables which are declared as Final Instance i.e. Final                                                 Instance Variable.

2. Final Static Variable -       Those variables which are declared as Final Static i.e. Final                                                     Static Variable.

3. Final Local Variable -        Those variables which are declared as Final Local i.e. Final                                                     Local Variables.
Note-  Final variable may or may not be initialized at declaration time.

4. Final Block Level Variable-  Those variables which are declared as Final block level i.e.                                                 Final Block Level Variable.

5. Final Parameterized Variable-  Those variables which are declared as Final parameter                                                   in method  i.e. known as Final Parameterized  Variable. 
Note-    'final' is the one of the unique access modifier in java ,that can be use inside method or method parameter.