C++ Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to C++ Framework. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - 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;
}

Q 2 - Choose the respective delete operator usage for the expression ‘ptr=new int[100]’.

Answer : C

Explaination

Q 3 - Runtime polymorphism is done using.

A - Function overloading

B - Virtual classes

C - Virtual functions

D - Friend function

Answer : C

Explaination

Virtual functions gives the ability to override the functionality of base class into the derived class. Hence achieving dynamic/runtime polymorphism.

Q 4 - How many number of arguments can a destructor of a class receives?

A - 0

B - 1

C - 2

D - None of the above.

Answer : A

Explaination

The destructor receives no arguments and is only form to be provided. Hence destructor cannot be overloaded.

Q 5 - What is the output of the following program?

#include<iostream>

using namespace std;
main() { 
   int const a = 5;
   
   a++; 
   cout<<a; 
}

Answer : D

Explaination

Compile error - constant variable cannot be modified.

Q 6 - HAS-A relationship between the classes is shown through.

A - Inheritance

B - Container classes

C - Polymorphism

D - None of the above.

Answer : B

Explaination

A class containing anther class object as its member is called as container class and exhibits HAS A relationship.

Q 7 - An exception is __

A - Runtime error

B - Compile time error

C - Logical error

D - None of the above

Answer : A

Explaination

When the program is in execution phase the possible unavoidable error is called as an exception.

Q 8 - What is the size of ‘int’?

A - 2

B - 4

C - 8

D - Compiler dependent

Answer : D

Explaination

The size of ‘int’ depends upon the complier i.e. whether it is a 16 bit or 32 bit.

Q 9 - What is the output of the following program?

#include<iostream>

using namespace std;
int x = 5;

int &f() {
	return x;
}
main() {
	f() = 10;
   cout<<x;
}

Answer : D

Explaination

A function can return reference, hence it can appear on the left hand side of the assignment operator.

#include<iostream>

using namespace std;
int x = 5;

int &f() {
	return x;
}
main() {
	f() = 10;
   cout<<x;
}

Q 10 - What is the output of the following program?

#include<iostream>

using namespace std;
void main() {
   char *s = "C++";
   
	cout<<s<<" ";
	s++;
	cout<<s<<" ";
}

Answer : B

Explaination

After s++, s points the string “++”.

#include<iostream>

using namespace std;
void main() {
   char *s = "C++";
   
	cout<<s<<" ";
	s++;
	cout<<s<<" ";
}

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