This is the c programming questions and answers section on "C Variables" with explanation for various interview, competitive examination and entrance test. Solved examples with detailed answer description, explanation are given and it would be easy to understand.
1. C99 standard guarantees uniqueness of ____ characters for internal names.
Answer: Option B
Explanation:
ISO C99 compiler may consider only first 63 characters for internal.
2. C99 standard guarantess uniqueness of _____ characters for external names.
Answer: Option A
Explanation:
ISO C99 compiler may consider only first 31 characters for external
variables having 31 characters due to which it may not be unique.
3. Which of the following is not a valid variable name declaration?
- A. int __a3;
- B. int __3a;
- C. int __A3;
- D. None of the mentioned.
Answer: Option D
Explanation:
None.
4. Which of the following is not a valid variable name declaration?
- A. int _a3;
- B. int a_3;
- C. int 3_a;
- D. int _3a
Answer: Option C
Explanation:
Variable name cannot start with a digit.
5. Variable names beginning with underscore is not encouraged. Why?
- A. It is not standardized
- B. To avoid conflicts since assemblers and loaders use such names
- C. To avoid conflicts since library routines use such names
- D. To avoid conflicts with environment variables of an operating system
Answer: Option C
Explanation:
None.
