OOP Concepts

Which one of the following are essential features of an object-oriented programming language? (GATE CS 2005) (i) Abstraction and encapsulation (ii) Strictly-typedness (iii) Type-safe property coupled with sub-type rule (iv) Polymorphism in the presence of inheritance

Which of the following language supports polymorphism but not the classes?

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

Which feature of OOP indicates code reusability?

Which one of the following are essential features of object oriented language? A. Abstraction and encapsulation B. Strictly-typed C. Type-safe property coupled with sub-type rule D. Polymorphism in the presence of inheritance

Which of the following is associated with objects?

Abstraction and encapsulation are fundamental principles that underlie the object-oriented approach to software development. What can you say about the following two statements?

I. Abstraction allows us to focus on what something does without considering the complexities of how it works.

II. Encapsulation allows us to bundle data and methods into a single unit and restrict direct access to an object's internal state.

The feature in object-oriented programming that allows the same operation to be carried out differently, depending on the object, is: