Constants and Variables in Java

A constant in Java is an unchangeable value give to a variable.

For example:

int AGE = 28;

public class ConstantExample {

        private static final int AGE = 28;
        public static void main(String args[])
        {

        System.out.println("Age ="+AGE);          

        }

}

The final keyword:
A final keyword tells Java compiler that the change in value assign to the variable is not allowed.

Constant naming conventions:
Use Upper case letters, for spaces use underscores.

For example:

int AGE = 28;

public keyword with constant:
It says that other classes in same Java project able to access the constant.

private keyword with constant:
It says that other classes in same Java project not able to access the constant.

static keyword with constant:
It makes constant accessible inside main().