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 - 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() { }

C - template<T>

    void abc<class T>::f() { }

D - template<T>

    void abc<T>::f() { }

Answer : A

Explaination

Answer : B

Explaination

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

Q 4 - What is the output of the following program?

#include<iostream>

using namespace std;
class Base {
public: 
   virtual void f() { 
      cout<<"Base\n";
   }
};

class Derived:public Base {
public: 
   void f() { 
      cout<<"Derived\n";
   }
};

main() { 
   Base *p = new Derived();
   p->f();

}

A - Base

B - Derived

C - Compile error

D - None of the above.

Answer : B

Explaination

The overridden method f() of the created object for derived class gets called.

#include<iostream>

using namespace std;
class Base {
public: 
   virtual void f() { 
      cout<<"Base\n";
   }
};

class Derived:public Base {
public: 
   void f() { 
      cout<<"Derived\n";
   }
};

main() { 
   Base *p = new Derived();
   p->f();

}

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

#include<iostream>

using namespace std;
class Base {
public:
   void f() {
      cout<<"Base\n";
   }
};
class Derived:public Base {
public:
   void f() {
      cout<<"Derived\n";
   }
};
main() { 
   Derived obj; 
   obj.Base::f();
}

A - Base

B - Derived

C - Compile error

D - None of the above.

Answer : A

Explaination

The method f() inherited from Base is referred using :: operator.

#include<iostream>

using namespace std;
class Base {
public:
   void f() {
      cout<<"Base\n";
   }
};
class Derived:public Base {
public:
   void f() {
      cout<<"Derived\n";
   }
};
main() { 
   Derived obj; 
   obj.Base::f();
}

Q 6 - An array can be passed to the function with call by value mechanism.

A - True

B - False

Answer : B

Explaination

An array never is passed with call by value mechanism

Answer : A

Explaination

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

Q 8 - What will be the output of the following program?

#include<iostream>
#include<string.h>

using namespace std;
main() {
   cout<<strcmp("strcmp()","strcmp()");
}

A - 0

B - 1

C - -1

D - Invalid use of strcmp() function

Answer : A

Explaination

0, strcmp return 0 if both the strings are equal

#include<iostream>
#include<string.h>

using namespace std;
main() {
   cout<<strcmp("strcmp()","strcmp()");
}

Q 9 - Following is the invalid inclusion of a file to the current program. Identify it

A - #include <file>

B - #include "file"

C - #include < file

D - All of the above are invalid

Answer : C

Explaination

option (a) & (b) are valid. There is no such syntax or provision as in option (c).

Q 10 - What is the built in library function to compare two strings?

A - string_cmp()

B - strcmp()

C - equals()

D - str_compare()

Answer : B

Explaination

strcmp() is the built in function from string.h to compare two strings. Returns 0 if both are same strings. Returns -1 if first < second string. Returns 1 first > second.

cpp_questions_answers.htm
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