GATE | GATE-CS-2003 | Question 76

Consider the following class definitions in a hypothetical Object Oriented language that supports inheritance and uses dynamic binding. The language should not be assumed to be either Java or C++, though the syntax is similar.

Class P
{
    void f(int i)
    {
        print(i);
    }
}

Class Q subclass of P
{
    void f(int i)
    {
        print(2*i);
    }
}

Now consider the following program fragment:

P x = new Q();
Q y = new Q();
P z = new Q();
x.f(1); ((P)y).f(1); z.f(1); 

Here ((P)y) denotes a typecast of y to P. The output produced by executing the above program fragment will be
(A) 1 2 1
(B) 2 1 1
(C) 2 1 2
(D) 2 2 2

Answer: (D)
Explanation: Since the question itself tells us that the language uses dynamic binding therefore all the function calls should be considered only on the basic of type of object stored.
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