Units

### Unit: Variable Length Argument - Questions and Answers

Practice these Variable Length Argument under C Programming walk-in interview Questions/ examination questions with best tricks and short cuts with solution. Student (candidate) who want to crack the walk in interview, competitive exams and want to find short cuts and tricks to solve questions on Variable Length Argument for following purpose.

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Here is list of Questions and Answers covering all key area of  Variable Length Argument topic of C Programming:

1.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    #include <stdarg.h>`
3. `    int f(int c, ...);`
4. `    int main()`
5. `    {`
6. `        int c = 97;`
7. `        float d = 98;`
8. `        f(c, d);`
9. `        return 0;`
10. `    }`
11. `    int f(int c, ...)`
12. `    {`
13. `        va_list li;`
14. `        va_start(li, c);`
15. `        float d = va_arg(li, float);`
16. `        printf("%f\n", d);`
17. `        va_end(li);`
18. `    }`

Explanation:

2.

Each call of va_arg

Explanation:

3.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    int f(char chr, ...);`
3. `    int main()`
4. `    {`
5. `        char c = 97;`
6. `        f(c);`
7. `        return 0;`
8. `    }`
9. `    int f(char c, ...)`
10. `    {`
11. `        printf("%c\n", c);`
12. `    }`

Explanation:

4.

Which of the following macro extracts an argument from the variable argument list (ie ellipsis)      and advance the pointer to the next argument?

Explanation:

5.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    #include <stdarg.h>`
3. `    int f(char c, ...);`
4. `    int main()`
5. `    {`
6. `        char c = 97, d = 98;`
7. `        f(c, d);`
8. `        return 0;`
9. `    }`
10. `    int f(char c, ...)`
11. `    {`
12. `        va_list li;`
13. `        va_start(li, c);`
14. `        char d = va_arg(li, char);`
15. `        printf("%c\n", d);`
16. `        va_end(li);`
17. `    }`

Explanation:

6.

The standard header _______ is used for variable list arguments (…) in C.

Explanation:

7.

va_end does whatever.

Explanation:

8.

The type va_list is used in an argument list

Explanation:

9.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    #include <stdarg.h>`
3. `    int f(...);`
4. `    int main()`
5. `    {`
6. `        char c = 97;`
7. `        f(c);`
8. `        return 0;`
9. `    }`
10. `    int f(...)`
11. `    {`
12. `        va_list li;`
13. `        char c = va_arg(li, char);`
14. `        printf("%c\n", c);`
15. `    }`

Explanation:

10.

Which of the following data-types are promoted when used as a parameter for an ellipsis?

Explanation:

11.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    #include <stdarg.h>`
3. `    void func(int, ...);`
4. `    int main()`
5. `    {`
6. `        func(2, 3, 5, 7, 11, 13);`
7. `        return 0;`
8. `    }`
9. `    void func(int n, ...)`
10. `    {`
11. `        int number, i = 0;`
12. `        va_list start;`
13. `        va_start(start, n);`
14. `        while (i != 3)`
15. `        {`
16. `            number = va_arg(start, int);`
17. `            i++;`
18. `        }`
19. `        printf("%d", number);`
20. `    }`

Explanation:

12.

What is the output of this C code?

1. `    #include <stdio.h>`
2. `    #include <stdarg.h>`
3. `    int f(char c, ...);`
4. `    int main()`
5. `    {`
6. `        char c = 97, d = 98;`
7. `        f(c, d);`
8. `        return 0;`
9. `    }`
10. `    int f(char c, ...)`
11. `    {`
12. `        va_list li;`
13. `        va_start(li, c);`
14. `        char d = va_arg(li, int);`
15. `        printf("%c\n", d);`
16. `        va_end(li);`
17. `    }`

Explanation:

13.

Which header file includes a function for variable number of arguments?

Explanation:

14.

The declaration … can