What is the output of this code and why?

Question

class A {
public void a() {
System.out.println("a() of class A");

}
}
class B extends A {
public void a() {
System.out.println("a() of class B");

}
}
class C extends B {
public static void main(String ar[]) {
C c=new C();
c.a();

}
}

I know the answer but I want to know how is it decided which a() has to be called?

Answer 1

Output should be: a() of class B

Explanation:
- main method calls a() of object c (of class C)
- C class doesn't have any a() method, so it checks its parent class B for a() method
- It gets a() in B, so executes it.
- Why doesn't it checks A? Because a() is an overridden method in B. Since B has its own a(), it doesn't look for a() in A class.

[Method overriding refers to the idea that if child class B contains a method of same prototype as its parent class A, then when the method will be called for child class, the overridden method will be executed, not the base method.]

Note: If C class has its own a() method, it'll call a() of C.

Answer 2

Shamima Yasmin thank you :)