C++ Programming Questions and Answers – Unspecified Number of Arguments

C++ Programming Multiple Choice Questions focuses on “Unspecified Number of Arguments”. One shall practice these questions to improve their C++ programming skills needed for various interviews exams and other competitive exams. These questions can be attempted by anyone focusing on learning C++ programming language. They can be a beginner, fresher, engineering graduate or an experienced IT professional. Our C++ questions comes with detailed explanation of the answers which helps in better understanding of C++ concepts.

C++ Programming Questions & Answers focuses on “Unspecified Number of Arguments” along with answers, explanations and/or solutions:

Q 1. Which header file is used to pass unknown number of arguments to function?
A. stdarg.h
B. string.h
C. stdlib.h
D. stdio.h

Show Answer

Answer:-A. stdarg.h

Explanation

Because the cstdarg defines this header file to process the unknown number of arguments.

Q 2. How can you access the arguments that are manipulated in the function?
A. arg_list
B. va_list
C. both va_list & arg_list
D. vg_list

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Answer:-B. va_list

Explanation

va_list is provided by C++ to access manipulated arguments in function.

Q 3. What will be the output of the following C++ code?

1. #include <iostream>
2. #include <stdarg.h>
3. using namespace std;
4. float avg( int Count, … )
5. {
6. va_list Numbers;
7. va_start(Numbers, Count);
8. int Sum = 0;
9. for (int i = 0; i < Count; ++i )
10. Sum += va_arg(Numbers, int);
11. va_end(Numbers);
12. return (Sum/Count);
13. }
14. int main()
15. {
16. float Average = avg(10, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
17. cout << “Average of first 10 whole numbers : ” << Average;
18. return 0;
19. }

A. 4
B. 5
C. 6
D. 7

Show Answer

Answer:-A. 4

Explanation

We are just calculating the average of these numbers using cstdarg. Output: $ g++ uka.cpp $ a.out Average of first 10 whole numbers 4

Q 4. What is the maximum number of arguments or parameters that can be present in one function call?
A. 64
B. 254
C. 255
D. 256

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Answer:-D. 256

Explanation

C++ allows maximum number of 256 arguments in a function call.

Q 5. What will be the output of the following C++ code?

1. #include <iostream>
2. #include <stdarg.h>
3. using namespace std;
4. int add (int num, …)
5. {
6. int sum = 0;
7. va_list args;
8. va_start (args,num);
9. for (int i = 0; i < num; i++)
10. {
11. int num = va_arg (args,int);
12. sum += num;
13. }
14. va_end (args);
15. return sum;
16. }
17. int main (void)
18. {
19. int total = add(8, 1, 2, -1, 4, 12, -2, 9, 7);
20. cout << “The result is ” << total;
21. return 0;
22. }

A. 23
B. 32
C. 48
D. compile time error

Show Answer

Answer:-B. 32

Explanation

We are adding these numbers by using for statement and stdarg. Output: $ g++ uka.cpp $ a.out The result is 32

Q 6. What will be the output of the following C++ code?

1. #include <iostream>
2. #include <stdarg.h>
3. using namespace std;
4. void dumplist(int, …);
5. int main()
6. {
7. dumplist(2, 4, 8);
8. dumplist(3, 6, 9, 7);
9. return 0;
10. }
11. void dumplist(int n, …)
12. {
13. va_list p;
14. int i;
15. va_start(p, n);
16. while (n–>0)
17. {
18. i = va_arg(p, int);
19. cout << i;
20. }
21. va_end(p);
22. }

A. 2436
B. 48697
C. 1111111
D. compile time error

Show Answer

Answer:-B. 48697

Explanation

In this program, we are eradicating the first value by comparing using while operator. Output: $ g++ rka3.cpp $ a.out 48697

Q 7. What will be the output of the following C++ code?

1. #include <iostream>
2. #include <stdarg.h>
3. using namespace std;
4. int flue(char c,…);
5. int main()
6. {
7. int x, y;
8. x = flue(‘A’, 1, 2, 3);
9. y = flue(‘1’, 1.0,1, ‘1’, 1.0f, 1l);
10. cout << x << y;
11. return 0;
12. }
13. int flue(char c,…)
14. {
15. return c;
16. }

A. 4965
B. 6549
C. 6646
D. compile time error

Show Answer

Answer:-B. 6549

Explanation

In this program, we are returning the ascii value of the character and printing it. Output: $ g++ rka4.cpp $ a.out 6549

Q 8. Which of the header file should be added in the following C++ code to properly run the program?

1. #include <iostream>
2. using namespace std;
3. int print_all (int num, …)
4. {
5. int sum = 0;
6. va_list args;
7. va_start (args,num);
8. for (int i = 0; i < num; i++)
9. {
10. int num = va_arg (args,int);
11. cout<<num<<” “;
12. }
13. va_end (args);
14. return sum;
15. }
16. int main (void)
17. {
18. print_all(8, 1, 2, -1, 4, 12, -2, 9, 7);
19. return 0;
20. }

A. stdlib.h
B. stdarg.h
C. string.h
D. stdpar.h

Show Answer

Answer:-B. stdarg.h

Explanation

header provided to perform variable number of argument passing.

Q 9. What will be the output of the following C++ code?

1. #include <iostream>
2. #include <stdarg.h>
3. using namespace std;
4. void fun(std::string msg, …);
5. int main()
6. {
7. fun(“IndiaBIX”, 1, 4, 7, 11, 0);
8. return 0;
9. }
10. void fun(std::string msg, …)
11. {
12. va_list ptr;
13. int num;
14. va_start(ptr, msg);
15. num = va_arg(ptr, int);
16. num = va_arg(ptr, int);
17. cout << num;
18. }

A. 4
B. 5
C. 6
D. 8

Show Answer

Answer:-A. 4

Explanation

In this program, we are moving the pointer to the second value and printing it. Output: $ g++ uka6.cpp $ a.out 4

Q 10. What will initialize the list of arguments in stdarg.h header file?
A. va_list
B. va_start
C. va_arg
D. vg_arg

Show Answer

Answer:-B. va_start

Explanation

va_start initialises the the list of arguments in header file.