C-Variable Numbers and Arguments Questions and Answers
C Variable Numbers and Arguments questions with answers help developers understand how functions in C can accept a varying number of parameters. Using standard macros like va_start, va_arg, and va_end, C programmers can design flexible functions similar to printf(). These programming questions and answers guide learners through the core logic and syntax used in handling variable arguments effectively. Such concepts are often asked in programming interview questions with answers during technical rounds in companies like Infosys, Tech Mahindra, and Wipro. Practicing C programming MCQs related to variable arguments helps build confidence in function handling and efficient coding techniques.
C-Variable Numbers and Arguments
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28 questions
11. In variable argument functions, how does the function know how many arguments were passed?
- It automatically knows from the function signature
- Through a separate count parameter or sentinel value
- By checking the stack size
- The compiler provides this information
12. Which standard library function commonly uses variable arguments?
- strlen
- malloc
- printf
- scanf
13. What happens if you call va_arg with the wrong type?
- The compiler gives an error
- It automatically converts the type
- It results in undefined behavior
- It returns NULL
14. Can variable argument functions have no fixed parameters?
- Yes, they can have only variable arguments
- No, at least one fixed parameter is required
- Only in C++
- It depends on the compiler
15. What is the correct order of using va macros?
- va_start → va_arg → va_end
- va_arg → va_start → va_end
- va_end → va_start → va_arg
- va_start → va_end → va_arg
16. Which data type promotions occur in variable arguments?
- No promotions occur
- char→int, float→double
- int→long, double→long double
- All types are promoted to void*
17. What is a common use case for variable arguments?
- Mathematical calculations
- Memory allocation
- Formatted output functions like printf
- File operations
18. Can you pass structures as variable arguments?
- No, structures are not allowed
- Yes, but only small structures
- Yes, but it is not portable and risky
- Only if they are passed by reference
19. What is the type of the va_list in most implementations?
- Integer
- Character pointer
- Void pointer
- Implementation-defined type
20. How can you determine the type of each variable argument?
- Using typeof operator
- Through a format string or convention
- va_arg automatically detects types
- By checking the argument size