CODEWITHSUNDEEP
javafinal
vidya
vidya

Reputation: 77

exact way how final methods works in java

class Clidder {
    private final void flipper() {
        System.out.println("Clidder");
    }
}
public class Clidlet extends Clidder {
    public final void flipper() {
        System.out.println("Clidlet");
    }
    public static void main(String args[]) {
        new Clidlet().flipper();
    }
}

what is the result? to this question I expected the answer "compilation fails" because final method cannot be overridden and it does not allow inheritance. but the answer was "Cliddet" why is that? did I misunderstand something in this concept. how can this be the output? please explain.

Upvotes: 5

Views: 254

Answers (4)

sixtytrees
sixtytrees

Reputation: 1233

In this case private keyword prevents subclass from accessing the method. As a result Clidlet asks Clidder about the method properties, receives response "I keep it private" and executes it's own method.

This case illustrate that the fact that private precedes (has higher priority than) final, that private final== private and demonstrates the confusion it can lead to.

Upvotes: 0

Mikhail Chibel
Mikhail Chibel

Reputation: 1955

The answer should be "Cliddet" as your final method has private access modifier which makes it invisible for the child class. The flipper method in the Clidlet class effectively hiding the same method in the parent class. This is quite dangerous as a result will depend on whether it is invoked from the superclass or the subclass. 

Clidlet  clidlet = new Clidlet();
clidlet.flipper(); // prints Clidlet

Clidder clidder = new Clidlet(); 
clidder.flipper(); // prints Clidder

Upvotes: 0

user207421
user207421

Reputation: 310885

private methods are not overridden, so there is no override here, so no violation of final. In fact final on a private method is meaningless, or redundant, take your pick.

Upvotes: 1

LynxZh
LynxZh

Reputation: 835

The private modifier indicates that the method of flipper() in class of Clidder can not be seen from child class Clidlet. So it is not overriding but just looks like a new method declaration in the child class. Private method/field can not be override because it can not be seen.

Upvotes: 4

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