C++ Mock Test
This section presents you various set of Mock Tests related to C++ Framework. You can download these sample mock tests at your local machine and solve offline at your convenience. Every mock test is supplied with a mock test key to let you verify the final score and grade yourself.
C++ Mock Test I
Q 1 - The default access specifer for the class members is
Answer : B
Explaination
If a member/s appear in the class with following no access specifier, the default is private.
Answer : C
Explaination
Few characters have alternative representation and start with ??. Eg. Fro [ equivalent is ??(
Q 3 - C++ does not supports the following
Answer : D
Explaination
C++ supports all the forms of inheritance.
Q 4 - One of the following is true for an inline function.
A - It executes faster as it is treated as a macro internally
B - It executes faster because it priority is more than normal function
C - It doesn’t executes faster compared to a normal function
Answer : A
Explaination
As inline function gets expanded at the line of call like a macro it executes faster.
Q 5 - Choose the pure virtual function definition from the following.
Answer : D
Explaination
A pure virtual function cannot have a definition.
Q 6 - Abstract class is __
A - A class must contain all pure virtual functions
B - A class must contain at least one pure virtual function
C - A class may not contain pure virtual function.
D - A class must contain pure virtual function defined outside the class.
Answer : B
Explaination
It is sufficient to have one pure virtual function in the class to make it as an abstract class.
Q 7 - What is the output of the following program?
#include<iostream>
using namespace std;
class abc {
void f();
void g();
int x;
};
main() {
cout<<sizeof(abc)<<endl;
}
Answer : B
Explaination
Only the class member variables constitutes as the size of the class or its object.
#include<iostream>
using namespace std;
class abc {
void f();
void g();
int x;
};
main() {
cout<<sizeof(abc)<<endl;
}
Q 8 - What is the output of the following program?
#include<iostream>
using namespace std;
class abc {
public:
static int x;
int i;
abc() {
i = ++x;
}
};
int abc::x;
main() {
abc m, n, p;
cout<<m.x<<" "<<m.i<<endl;
}
Answer : A
Explaination
The static member variable ‘x’ shares common memory among all the objects created for the class.
#include<iostream>
using namespace std;
class abc {
public:
static int x;
int i;
abc() {
i = ++x;
}
};
int abc::x;
main() {
abc m, n, p;
cout<<m.x<<" "<<m.i<<endl;
}
Answer : B
Explaination
The purpose of the constructor cannot be overridden in the derived class hence constructor cannot be a virtual.
Answer : C
Explaination
Scope resolution (::) is not permitted to be overloaded.
Q 11 - Which operator is required to be overloaded as member function only?
Answer : D
Explaination
Overloaded assignment operator does the job similar to copy constructor and is required to be overloaded as member function of the class.
Q 12 - Which of the following is not the keyword in C++?
Answer : C
Explaination
All the rest are valid keywords of C++.
Q 13 - What is the output of the following program?
#include<iostream>
using namespace std;
class abc {
public:
int i;
abc(int i) {
i = i;
}
};
main() {
abc m(5);
cout<<m.i;
}
Answer : B
Explaination
i=i, is assigning member variable to itself.
#include<iostream>
using namespace std;
class abc {
public:
int i;
abc(int i) {
i = i;
}
};
main() {
abc m(5);
cout<<m.i;
}
Q 14 - By default the members of the structure are
Answer : C
Explaination
If no access specifiers are specified for structure variables/functions, then the default is considered as public.
Q 15 - From the below class choose the proper definition of the member function f().
template <class T>
class abc {
void f();
};
A - template <class T> void abc<T>::f() { }
B - template<class T> void abc::f() { }
Answer : A
Explaination
Q 16 - Choose the respective delete operator usage for the expression ‘ptr=new int[100]’.
Answer : C
Explaination
Answer : B
Explaination
It’s an object of istream class.
Q 18 - The operator used to access member function of a structure using its object.
Answer : A
Explaination
Just the way we use dot (.) operator to access members of the class, in similar it is used to access the members of the structure too.
Q 19 - A user defined header file is included by following statement in general.
Answer : A
Explaination
With the syntax as in (a) the compiler first looks for the file in the present working directory and then in the default include path if not found.
Q 20 - Which data type can be used to hold a wide character in C++?
Answer : C
Explaination
wchar_t is the data type using which we can hold Unicode characters.
Q 21 - Which is the storage specifier used to modify the member variable even though the class object is a constant object?
Answer : D
Explaination
mutable is storage specifier introduced in C++ which is not available in C. A class member declared with mutable is modifiable though the object is constant.
Q 22 - The following operator can be used to calculate the value of one number raised to another.
Answer : D
Explaination
There is no such operator in C/C++.
Q 23 - Pick up the valid declaration for overloading ++ in postfix form where T is the class name.
Answer : B
Explaination
The parameter int is just to signify that it is the postfix form overloaded. Shouldn’t return reference as per its original behavior.
Q 24 - We can have varying number of arguments for the overloaded form of () operator.
Answer : A
Explaination
Q 25 - Operators sizeof and ?:
Answer : B
Explaination
Both the mentioned operators cannot be overloaded.
Answer Sheet
| Question Number | Answer Key |
|---|---|
| 1 | B |
| 2 | C |
| 3 | D |
| 4 | A |
| 5 | D |
| 6 | B |
| 7 | B |
| 8 | A |
| 9 | B |
| 10 | C |
| 11 | D |
| 12 | C |
| 13 | B |
| 14 | C |
| 15 | A |
| 16 | C |
| 17 | B |
| 18 | A |
| 19 | A |
| 20 | C |
| 21 | D |
| 22 | D |
| 23 | B |
| 24 | A |
| 25 | B |
