super class

[Arivu Selvi]

Can anybody explain how the output here is 22?

class Base {
int i;
Base() { add(1); }
void add(int v) { i += v; }
void print() { System.out.println(i); }
}

class Extension extends Base {
Extension() { add(2); }
void add(int v) { i += v*2; }
}

public class Qd073 {
public static void main(String[] args) {
bogo(new Extension());
}
static void bogo(Base b) {
b.add(8);
b.print();
}
}

[Joe Harry]

This question is explained in the Khalid Mughal's book itself.

[Vishal K Patel]

Here, when the

new Extension()

is called, automatically super constructor will be called.

Form the super constructor, add method is called with argument 1. but the method from child class will be executed at run time as the original object is from child class.

This is the good example of polymorphisms.

I think it's enough to get the reason.....