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 - Choose the pure virtual function definition from the following.

A - virtual void f()=0 { }

B - void virtual f()=0 { }

C - virtual void f() {} = 0;

D - None of the above.

Answer : D

Explaination

A pure virtual function cannot have a definition.

Q 2 - Which of the following is not the keyword in C++?

A - volatile

B - friend

C - extends

D - this

Answer : C

Explaination

All the rest are valid keywords of C++.

Answer : B

Explaination

Only members of the derived class and the same class can access a protected member.

Answer : D

Explaination

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";
}

Q 6 - i) single file can be opened by several streams simultaneously.

ii) several files simultaneously can be opened by a single stream

A - (i) and (ii) are true

B - (i) and (ii) are false

C - Only (i) is true

D - Only (ii) is true

Answer : C

Explaination

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

#include<iostream>

using namespace std;
void f() {
   cout<<"Hello"<<endl;
}
main() {
}

A - No output

B - Error, as the function is not called.

C - Error, as the function is defined without its declaration

D - Error, as the main() function is left empty

Answer : A

Explaination

No output, apart from the option (a) rest of the comments against the options are invalid

#include<iostream>

using namespace std;
void f() {
	cout<<"Hello"<<endl;
}
main() 
{
}

Q 8 - What is the size of the following union definition?

#include<iostream>

using namespace std;
main() {
   union abc { 
      char a, b, c, d, e, f, g, h; 
      
      int i;
   };
   cout<<sizeof(abc);
}

A - 1

B - 2

C - 4

D - 8

Answer : C

Explaination

union size is biggest element size of it. All the elements of the union share common memory.

#include<iostream>

using namespace std;
main() {
   union abc { 
      char a, b, c, d, e, f, g, h; 
      
      int i;
   };
   cout<<sizeof(abc);
}

Q 9 - Special symbol permitted with in the identifier name.

A - $

B - @

C - _

D - .

Answer : C

Explaination

The only permitted special symbol is under score (_) in the identifier.

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 : D

Explaination

s refers to a constant address and cannot be incremented.

#include<iostream>

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