'final' instance variable

If an instance variable is declared as 'final' , then the instance  variable will behave like a constant  by preventing its value from being modified.

Note - As per the coding convention, we've to mention the instance variables specified as 'final' in upper case as shown below:

     final int COUNT = 5;

Lets implement this on Eclipse IDE:

1. Create a class 'FinalDemo' under any project as shown below:



2. Declare an instance variable 'COUNT' and specify it as 'final' as shown below:



3. Try to re-assign a different value to 'COUNT' variable which is specified as 'final' as shown below:


4. Observe that an error is displayed and hover your mouse over the error to read the error details as shown  below:



After looking at this error, its very clear that  instance variables specified as 'final' can be assigned a value only once.

Note - 'final' is one of the non-access specifiers in Java.