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.

Questions and Answers

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;
}

A - 3 1

B - 3 3

C - 1 1

D - 1 3

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 - Which operator is required to be overloaded as member function only?

A - _

B - _ _

C - ++ (postfix version)

D - =

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 3 - What is the output of the following program?

#include<iostream>

using namespace std;
main() { 

   int i = 1, j = 2, k = 3, r; 

   r = (i, j, k);

   cout<<r<<endl;

}

A - 1

B - 2

C - 3

D - Compile Error

Answer : C

Explaination

Comma is called as the separator operator and the associativity is from left to right. Therefore k is the expressions resultant.

#include<iostream>

using namespace std;
main() { 

   int i = 1, j = 2, k = 3, r; 

   r = (i, j, k);

   cout<<r<<endl;

}

Answer : A

Explaination

There are no keywords in C++ such as abstract and interface.

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

#include<iostream>

using namespace std;
main() { 
   int *p = new int; 
   delete p; 
   delete p; 
   cout<<"Done";
}

A - Done

B - Compile error

C - Runtime error

D - None of the above

Answer : C

Explaination

It is invalid to release memory more than once.

#include<iostream>

using namespace std;
main() { 
   int *p = new int; 
   delete p; 
   delete p; 
   cout<<"Done";
}

Answer : A

Explaination

Q 7 - What is the outpout of the following program?

#include<iostream>

using namespace std;
main() {
   enum { 
      india, is = 7, GREAT 
   };

   cout<<india<<" "<<GREAT;
}

A - 0 1

B - 0 2

C - 0 8

D - Compile error

Answer : C

Explaination

0 8, enums gives the sequence starting with 0. If assigned with a value the sequence continues from the assigned value.

#include<iostream>

using namespace std;
main() {
   enum { 
      india, is = 7, GREAT 
   };

   cout<<india<<" "<<GREAT;
}

Q 8 - What is the output of the following program?

#include<iostream>

using namespace std;
main() { 
   int r, x = 2;
   
   float y = 5;
  
   r = y%x;
   cout<<r; 
}

A - 1

B - 0

C - 2

D - Compile error

Answer : D

Explaination

Answer Compile Error, It is invalid that either of the operands for the modulus operator (%) is a real number.

#include<iostream>

using namespace std;
main() { 
   int r, x = 2;
   
   float y = 5;
  
   r = y%x;
   cout<<r; 
}

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;
}

A - 5

B - Address of x

C - Compile error

D - 10

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<<" ";
}

A - C++ C++

B - C++ ++

C - ++ ++

D - Compile error

Answer : B

Explaination

After s++, s points the string ++.

#include<iostream>

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