Questions and answers for exam Preparation

MCQs

Total Questions : 10

Question 1.

Where does the abstract class is used?

base class only
derived class
both a & b
None of the mentioned

Discuss Question

Answer: Option A. -> base class only

None.

Question 2.

Pick out the correct option.

We cannot make an instance of an abstract base class
We can make an instance of an abstract base class
Both a & b
None of the mentioned

Discuss Question

Answer: Option A. -> We cannot make an instance of an abstract base class

None

Question 3.

What is meant by pure virtual function?

Function which does not have definition of its own.
Function which does have definition of its own.
Function which does not have any return type.
None of the mentioned

Discuss Question

Answer: Option A. -> Function which does not have definition of its own.

As the name itself implies, it have to depend on other class only.

Question 4.

What is the output of this program?

1.
#include
2.
using namespace std;
3.
class Base
4.
{
5.
public:
6.
virtual void print() const = 0;
7.
};
8.
class DerivedOne : virtual public Base
9.
{
10.
public:
11.
void print() const
12.
{
13.
cout

121
212
12
None of the mentioned

Discuss Question

Answer: Option B. -> 212

In this program, We are executing these based on the condition given in array. So it is printing as 212.
Output:
$ g++ abs4.cpp
$ a.out
212

Question 5.

What is the output of this program?

1.
#include
2.
using namespace std;
3.
class sample
4.
{
5.
public:
6.
virtual void example() = 0;
7.
};
8.
class Ex1:public sample
9.
{
10.
public:
11.
void example()
12.
{
13.
cout example();
33.
}

ubuntu
is awesome
ubuntu is awesome
None of the mentioned

Discuss Question

Answer: Option C. -> ubuntu is awesome

In this program, We are combining the two statements from two classes and printing it by

using abstract class.
Output:
$ g++ abs3.cpp
$ a.out
ubuntu is awesome

Question 6.

What is the output of this program?

1.
#include
2.
using namespace std;
3.
class MyInterface
4.
{
5.
public:
6.
virtual void Display() = 0;
7.
};
8.
class Class1 : public MyInterface
9.
{
10.
public:
11.
void Display()
12.
{
13.
int a = 5;
14.
cout

5
10
5 5
None of the mentioned

Discuss Question

Answer: Option C. -> 5 5

In this program, We are displaying the data from the two classes
by using abstract class.
Output:
$ g++ abs1.cpp
$ a.out
5 5

Question 7.

What is the output of this program?

1.
#include
2.
using namespace std;
3.
class p
4.
{
5.
protected:
6.
int width, height;
7.
public:
8.
void set_values (int a, int b)
9.
{
10.
width = a; height = b;
11.
}
12.
virtual int area (void) = 0;
13.
};
14.
class r: public
15.
{
16.
public:
17.
int area (void)
18.
{
19.
return (width * height);
20.
}
21.
};
22.
class t: public p
23.
{
24.
public:
25.
int area (void)
26.
{
27.
return (width * height / 2);
28.
}
29.
};
30.
int main ()
31.
{
32.
r rect;
33.
t trgl;
34.
p * ppoly1 = &rect;
35.
p * ppoly2 = &trgl;
36.
ppoly1->set_values (4, 5);
37.
ppoly2->set_values (4, 5);
38.
cout area() ;
39.
cout area();
40.
return 0;
41.
}