Difference between static and final

ravikumar681 · May 26th, 2004, 08:48 AM

<P>
hai ,

please tell me wat is the difference between static and final varibles
, static and final class.

thanks in advance for your replies
i need help under what situtation static is useful and final is useful.

<p>

taec · June 2nd, 2004, 01:56 PM

the ``final'' keyword, when applied to a variable, means the variable's value is constant.

e.g.

Code:

    final int RED = 1;

the variable RED cannot now be given another value. If you are familiar with C, it is analogous to the following:

Code:

    #define RED 1

The ``final'' keyword is useful when applied to variables whose values will not change during the lifetime of the program. If you've got constant values in your program which will not change throughout, it is useful to declare them as final.

The keyword ``static'' when applied to a variable OR a method means that the variable or method can be accessed without creating an instance of the class.

For examples of static variables see the Color class in the Java API. It uses static variables such as BLACK, BLUE, PINK etc.
They can be referenced like:

Code:

    useColor(Color.BLACK);

instead of

Code:

    Color myColorBlack = new Color();
    useColor(myColorBlack.BLACK);

static can be used for methods for much the same effect.

When ``final'' is applied to a class, the principle effect is that the class cannot be inherited from. For example, the following would throw an error:

Code:

   public final class Dog {
     public Dog() {
     }
   }

   public class JackRussell extends Dog {
      public JackRussell() {
      }
   }

For more information on the static keyword, see:
http://www.javacoffeebreak.com/faq/faq0010.html

Phil

svijay_siva · June 24th, 2004, 07:54 AM

static means the reference is constant whereas final means the value is constant

Vijay