C++ Programming MCQ (Multiple Choice Questions)

Here are 1000 MCQs on C++ (Chapterwise).

1. Who invented C++?
a) Dennis Ritchie
b) Ken Thompson
c) Brian Kernighan
d) Bjarne Stroustrup
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2. What is C++?
a) C++ is an object oriented programming language
b) C++ is a procedural programming language
c) C++ supports both procedural and object oriented programming language
d) C++ is a functional programming language
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3. Which of the following is the correct syntax of including a user defined header files in C++?
a) #include [userdefined]
b) #include “userdefined”
c) #include <userdefined.h>
d) #include <userdefined>
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4. Which of the following is used for comments in C++?
a) /* comment */
b) // comment */
c) // comment
d) both // comment or /* comment */
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5. Which of the following user-defined header file extension used in c++?
a) hg
b) cpp
c) h
d) hf
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6. Which of the following is a correct identifier in C++?
a) VAR_1234
b) $var_name
c) 7VARNAME
d) 7var_name
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7. Which of the following is not a type of Constructor in C++?
a) Default constructor
b) Parameterized constructor
c) Copy constructor
d) Friend constructor
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8. Which of the following approach is used by C++?
a) Left-right
b) Right-left
c) Bottom-up
d) Top-down
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9. What is virtual inheritance in C++?
a) C++ technique to enhance multiple inheritance
b) C++ technique to ensure that a private member of the base class can be accessed somehow
c) C++ technique to avoid multiple inheritances of classes
d) C++ technique to avoid multiple copies of the base class into children/derived class
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10. What happens if the following C++ statement is compiled and executed?

int *ptr = NULL;
delete ptr;

a) The program is not semantically correct
b) The program is compiled and executed successfully
c) The program gives a compile-time error
d) The program compiled successfully but throws an error during run-time
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11. What will be the output of the following C++ code?

#include <iostream> 
#include <string>
using namespace std; 
int main(int argc, char const *argv[])
{
	char s1[6] = "Hello";
	char s2[6] = "World";
	char s3[12] = s1 + " " + s2;
	cout<<s3;
	return 0;
}

a) Hello
b) World
c) Error
d) Hello World
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12. What is the difference between delete and delete[] in C++?
a) delete is syntactically correct but delete[] is wrong and hence will give an error if used in any case
b) delete is used to delete normal objects whereas delete[] is used to pointer objects
c) delete is a keyword whereas delete[] is an identifier
d) delete is used to delete single object whereas delete[] is used to multiple(array/pointer of) objects
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13. What happens if the following program is executed in C and C++?

#include <stdio.h> 
int main(void) 
{ 
	int new = 5;
	printf("%d", new); 
}

a) Error in C and successful execution in C++
b) Error in both C and C++
c) Error in C++ and successful execution in C
d) A successful run in both C and C++
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14. What happens if the following program is executed in C and C++?

#include <stdio.h> 
void func(void)
{
	printf("Hello");
}
void main() 
{ 
	func();
	func(2);
}

a) Outputs Hello twice in both C and C++
b) Error in C and successful execution in C++
c) Error in C++ and successful execution in C
d) Error in both C and C++
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15. Which of the following is correct about this pointer in C++?
a) this pointer is passed as a hidden argument in all static variables of a class
b) this pointer is passed as a hidden argument in all the functions of a class
c) this pointer is passed as a hidden argument in all non-static functions of a class
d) this pointer is passed as a hidden argument in all static functions of a class
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16. What will be the output of the following C++ code?

a) spacesintext
b) spaces in text
c) spaces
d) spaces in
View Answer

$ g++ dan.cpp
$ a.out
spacesintext

17. Which of the following C++ code will give error on compilation?

================code 1=================
#include <iostream>
using namespace std;
int main(int argc, char const *argv[])
{
	cout<<"Hello World";
	return 0;
}
========================================
================code 2=================
#include <iostream>
int main(int argc, char const *argv[])
{
	std::cout<<"Hello World";
	return 0;
}
========================================

a) Code 1 only
b) Neither code 1 nor code 2
c) Both code 1 and code 2
d) Code 2 only
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18. Which of the following type is provided by C++ but not C?
a) double
b) float
c) int
d) bool
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19. What is the value of p in the following C++ code snippet?

a) 12
b) 0
c) 2
d) 16
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20. By default, all the files in C++ are opened in _________ mode.
a) Binary
b) VTC
c) Text
d) ISCII
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21. What will be the output of the following C++ function?

a) Runtime error may be possible
b) Compiler error may be possible
c) 1
d) 0
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22. Which of the following correctly declares an array in C++?
a) array{10};
b) array array[10];
c) int array;
d) int array[10];
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23. What is the size of wchar_t in C++?
a) Based on the number of bits in the system
b) 2 or 4
c) 4
d) 2
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24. What will be the output of the following C++ code?

#include<iostream>
using namespace std;
int main ()
{
   int cin;
   cin >> cin;
   cout << "cin: " << cin;
   return 0;
}

a) Segmentation fault
b) Nothing is printed
c) Error
d) cin: garbage value
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25. What is the use of the indentation in c++?
a) r distinguishes between comments and inner data
b) distinguishes between comments and outer data
c) distinguishes between comments and code
d) r distinguishes between comments and outer data
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26. Which is more effective while calling the C++ functions?
a) call by object
b) call by pointer
c) call by value
d) call by reference
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27. What will be the output of the following C++ program?

#include <iostream> 
#include <string>
#include <cstring>
using namespace std; 
int main(int argc, char const *argv[])
{
	const char *a = "Hello\0World";
	cout<<a;
	return 0;
}

a) Hello
b) World
c) Error
d) Hello World
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28. Which of the following is used to terminate the function declaration in C++?
a) ;
b) ]
c) )
d) :
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29. What will be the output of the following C++ code?

a) I
b) J
c) A
d) N
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30. What will be the output of the following C++ program?

a) compile time error
b) 0.100001
c) 0.11
d) 0.10000000000000001
View Answer

$ g++ float2.out
$ a.out
0.10000000000000001

31. Which keyword is used to define the macros in c++?
a) #macro
b) #define
c) macro
d) define
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32. What is the correct syntax of accessing a static member of a class in C++?

---------------------------
Example class:
class A
{
	public:
		static int value;
}
---------------------------

a) A->value
b) A^value
c) A.value
d) A::value
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33. The C++ code which causes abnormal termination/behaviour of a program should be written under _________ block.
a) catch
b) throw
c) try
d) finally
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34. What is Inheritance in C++?
a) Deriving new classes from existing classes
b) Overloading of classes
c) Classes with same names
d) Wrapping of data into a single class
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35. What will be the output of the following C++ code?

a) 2 5
b) 4 5
c) 4 6
d) 2 6
View Answer

$ g++ size3.cpp
$ a.out
4 5

36. Which of the following symbol is used to declare the preprocessor directives in C++?
a) $
b) ^
c) #
d) *
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37. What will be the output of the following C++ program?

#include<iostream>
using namespace std;
int main()
{
	int a = 5;
	auto check = [=]() 
        {
		a = 10;
	};
	check();
	cout<<"Value of a: "<<a<<endl;
	return 0;
}

a) Segmentation fault
b) Value of a: 5
c) Value of a: 10
d) Error
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38. What will be the output of the following C++ code?

#include <iostream>
using namespace std;
void square (int *x, int *y)
{
	*x = (*x) * --(*y);
}
int main ( )
{
	int number = 30;
	square(&number, &number);
	cout << number;
	return 0;
}

a) 30
b) Error
c) Segmentation fault
d) 870
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39. What is meant by a polymorphism in C++?
a) class having only single form
b) class having four forms
c) class having many forms
d) class having two forms
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40. What will be the output of the following C++ program?

#include <iostream>
#include <string>
using namespace std;
int main ()
{
  std::string str ("Sanfoundry.");
  str.back() = '!';
  std::cout << str << endl;
  return 0;
}

a) Sanfoundry!
b) Sanfoundry!.
c) Sanfoundry.
d) Sanfoundry.!
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41. Pick the incorrect statement about inline functions in C++?
a) Saves overhead of a return call from a function
b) They are generally very large and complicated function
c) These functions are inserted/substituted at the point of call
d) They reduce function call overheads
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42. What will be the output of the following C++ program?

a) 5
b) 6
c) compile time error
d) runtime error
View Answer

$ g++ poi1.cpp
$ a.out
5

43. What is abstract class in C++?
a) Any Class in C++ is an abstract class
b) Class from which any class is derived
c) Class specifically used as a base class with atleast one virtual functions
d) Class specifically used as a base class with atleast one pure virtual functions
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44. Which of the following constructors are provided by the C++ compiler if not defined in a class?
a) Copy constructor
b) Default constructor
c) Assignment constructor
d) All of the mentioned
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45. What will be the output of the following C++ program?

#include <iostream>
using namespace std; 
int main()
{
    try
    {
        try
        {
            throw 20;
        }
        catch (int n)
        {
            cout << "Inner Catch\n";
            throw;
        }
    }
    catch (int x)
    {
        cout << "Outer Catch\n";
    }
    return 0;
}

a) Outer Catch
b)

Inner Catch
Outer Catch

c) Error
d) Inner Catch
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46. Which concept allows you to reuse the written code in C++?
a) Inheritance
b) Polymorphism
c) Abstraction
d) Encapsulation
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47. What will be the output of the following C++ code snippet?

a) 10.0 5
b) 10 2.5
c) 10.0 5.0
d) 5.0 2.5
View Answer

$ g++ over3.cpp
$ a.out
10	2.5

48. How structures and classes in C++ differ?
a) Structures by default hide every member whereas classes do not
b) In Structures, members are public by default whereas, in Classes, they are private by default
c) Structures cannot have private members whereas classes can have
d) In Structures, members are private by default whereas, in Classes, they are public by default
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49. What will be the output of the following C++ code?

a) 12
b) 14
c) 6
d) 7
View Answer

$ g++ ess1.cpp
$ a.out
7

50. What is the benefit of c++ input and output over c input and output?
a) Both Type safety & Exception
b) Sequence container
c) Exception
d) Type safety
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51. What will be the output of the following C++ code snippet?

a) 21
b) 27
c) 26
d) 25
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52. What will be the output of the following C++ program?

a) runtime error
b) Sanfo
c) S
d) Sanfoundry
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53. What will be the output of the following C++ program?

#include <iostream>
using namespace std;
class A{
public:
	A(){
		cout<<"Constructor called\n";
	   }
	~A(){
		cout<<"Destructor called\n";
	    } 
};
int main(int argc, char const *argv[])
{
	A *a = new A[5];
	delete[] a;
	return 0;
}

a) Segmentation fault
b) “Constructor called” five times and then “Destructor called” five times
c) “Constructor called” five times and then “Destructor called” once
d) Error
View Answer

1. C++ Basic Concepts
2. C++ Types, Pointers, Arrays & Structures
3. C++ Functions, Namespaces & Exceptions
4. C++ Source Files, Classes and Operator Overloading
5. C++ Derived Classes, C++ Templates & Exception Handling
6. C++ Class Hierarchies, C++ Library & Containers
7. C++ Algorithms, Objects & Iterators
8. C++ Strings, Streams & Numerics
9. Advanced C++

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