C++ MCQs

1. Which of the following is the correct syntax to output "Hello World" in C++?
   a) echo "Hello World";
   b) Console.WriteLine("Hello World");
   c) cout << "Hello World";
   d) printf("Hello World");
   Answer: c

2. Which of the following is not a C++ keyword?
   a) public
   b) private
   c) protected
   d) then
   Answer: d

3. Which of the following is the correct file extension for C++ source files?
   a) .cp
   b) .cpp
   c) .cxx
   d) Both b and c
   Answer: d

4. What is the default return type of a function in C++ if not specified?
   a) int
   b) void
   c) float
   d) double
   Answer: a

5. Which of the following is used to comment a single line in C++?
   a) /* comment */
   b) // comment
   c) # comment
   d) -- comment
   Answer: b

6. Which header file is required for using cout and cin?
   a) <iostream.h>
   b) <stdio.h>
   c) <iostream>
   d) <conio.h>
   Answer: c

7. Which of the following is not a basic data type in C++?
   a) int
   b) float
   c) bool
   d) real
   Answer: d

8. Which operator is used for scope resolution in C++?
   a) ::
   b) .
   c) ->
   d) :
   Answer: a

9. Which of the following is the correct way to declare a constant in C++?
   a) const int x = 10;
   b) int const x = 10;
   c) #define x 10
   d) All of the above
   Answer: d

10. What does the main() function return in C++ by default?
    a) 1
    b) 0
    c) void
    d) None
    Answer: b

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11–20: Control Structures

11. Which loop is guaranteed to execute at least once?
    a) for
    b) while
    c) do-while
    d) None of the above
    Answer: c

12. Which statement is used to skip the current iteration in a loop?
    a) exit
    b) break
    c) continue
    d) return
    Answer: c

13. What is the output of: for(int i=0;i<5;i++){ cout << i; }?
    a) 12345
    b) 01234
    c) 1234
    d) 012345
    Answer: b

14. Which keyword is used to return a value from a function?
    a) break
    b) goto
    c) return
    d) exit
    Answer: c

15. Which of the following is used to terminate a switch statement?
    a) return
    b) exit
    c) break
    d) goto
    Answer: c

16. What is the purpose of the default keyword in a switch case?
    a) It ends the switch block.
    b) It is executed if no other case matches.
    c) It is always executed first.
    d) None of the above
    Answer: b

17. Which of the following is not a relational operator?
    a) !=
    b) ==
    c) =
    d) >=
    Answer: c

18. Which of the following loops is entry-controlled?
    a) do-while
    b) while
    c) Both a and b
    d) None
    Answer: b

19. What is the output of: if (0) cout << "Hi"; else cout << "Bye";?
    a) Hi
    b) Bye
    c) 0
    d) Error
    Answer: b

20. Which operator is used to check both conditions in an if statement?
    a) &
    b) &&
    c) |
    d) ||
    Answer: b