Program to demonstrate the use of 'final' keyword
In Java, the final keyword is used for three purposes:
- It is used to declare a variable as a constant.
- It is used to prevent method overriding.
- It is used to prevent inheritance.
We can declare a variable in any scope to be final. The value of final variable cannot change after it has been initialized. To declare a final variable, we use the final keyword in the variable declaration before the types.
final type <variable-name> = value;
PROGRAM
class A {
void show() {
System.out.println("Inside A");
}
}
class B extends A {
final double PI = 3.14;
int x = 10;
void show() {
System.out.println("Inside B");
x = 20;
System.out.println("x = "+x);
System.out.println("PI = "+PI);
}
public static void main(String args[]) {
B objB = new B();
objB.show();
A objA = new A();
objA.show();
}
}
OUTPUT
C:\>javac B.java C:\>java B Inside B x = 20 PI = 3.14 Inside A