Questions and answers for exam Preparation

MCQs

Total Questions : 10

Question 1.

At which time does the static_cast can be applied?

Compile-time construct
Runtime construct
Both a & b
None of the mentioned

Discuss Question

Answer: Option A. -> Compile-time construct

Static_cast can be applied to only compile-time construct and not during run time construct.

Question 2.

What is meant by type_info?

Used to hold the type information returned by the typeid operator
Used to hold the type information returned by the dynamic_cast
Used to hold the type information returned by the static cast
None of the mentioned

Discuss Question

Answer: Option A. -> Used to hold the type information returned by the typeid operator

None.

Question 3.

What is the output of this program?

1.
#include
2.
using namespace std;
3.
struct A
4.
{
5.
virtual void f()
6.
{
7.
cout

Class C
Class A
Both a & b
None of the mentioned

Discuss Question

Answer: Option C. -> Both a & b

In this program, We applied the dynamic casting to structure and produced the output.
Output:
$ g++ rtti4.cpp
$ a.out
Class C
Class A

Question 4.

What is the output of this program?

1.
#include
2.
#include
3.
using namespace std;
4.
class A
5.
{
6.
public:
7.
virtual ~A();
8.
};
9.
int main()
10.
{
11.
A* a = NULL;
12.
try
13.
{
14.
cout

int
float
double
object is NULL

Discuss Question

Answer: Option D. -> object is NULL

In this program, We are using the bad typeid() for a. So it is arising an exception.
Output:
$ g++ rtti3.cpp
$ a.out
object is NULL

Question 5.

What is the output of this program?

1.
#include
2.
#include
3.
#include
4.
using namespace std;
5.
class base
6.
{
7.
virtual void f(){}
8.
};
9.
class derived : public base {};
10.
int main ()
11.
{
12.
try
13.
{
14.
base* a = new base;
15.
base* b = new derived;
16.
cout

base*
derived*
4base and 7derived
None of the mentioned

Discuss Question

Answer: Option C. -> 4base and 7derived

In this program, We apply the typeid to the polymorphic class.
Output:
$ g++ rtti2.cpp
$ a.out
4base 7derived

Question 6.

What is the output of this program?

1.
#include
2.
#include
3.
using namespace std;
4.
int main ()
5.
{
6.
int * a;
7.
int b;
8.
a = 0; b = 0;
9.
if (typeid(a) != typeid(b))
10.
{
11.
cout

Pi
i
Both a & b
f

Discuss Question

Answer: Option C. -> Both a & b

In this program, We are finding the typeid of the given variables.
Output:
$ g++ rtti1.cpp
$ a.out
Pii

Question 7.

Which operators are part of RTTI?

dynamic_cast()
typeid
Both a & b
None of the mentioned

Discuss Question

Answer: Option C. -> Both a & b

The dynamic_cast<> operation and typeid operator in C++ are part of RTTI.

Question 8.

What is the output of this program?

1.
#include
2.
#include
3.
using namespace std;
4.
class base { virtual void dummy() {} };
5.
class derived: public base { int a; };
6.
int main ()
7.
{
8.
try
9.
{
10.
base * pba = new derived;
11.
base * pbb = new base;
12.
derived * pd;
13.
pd = dynamic_cast(pba);
14.
if (pd == 0)
15.
cout