Question

Consider the following C function definition. \begin{verbatim} int fX(char *a){ char *b = a; while(*b) b++; return b - a; } \end{verbatim} Which of the following statements is/are TRUE?

• A. The function call \texttt{fX("abcd")} will always return a value
• B. Assuming a character array \texttt{c} is declared as \texttt{char c[] = "abcd"} in \texttt{main()}, the function call \texttt{fX(c)} will always return a value
• C. The code of the function will not compile
• D. Assuming a character pointer \texttt{c} is declared as \texttt{char *c = "abcd"} in \texttt{main()}, the function call \texttt{fX(c)} will always return a value

Hint:

String literals and character arrays can be used as inputs to functions that calculate string lengths, provided they are properly null-terminated.

Answer 1

The Correct Option is A

Option (A): The string literal \texttt{"abcd"} is valid, and the function calculates the length of the string by iterating until the null character. Hence, Option (A) is correct.
Option (B): The character array \texttt{c} is a valid input for the function, and the function correctly calculates the length of the string. Hence, Option (B) is correct.
Option (C): This is false. The code is valid and will compile without any issues. Hence, Option (C) is incorrect.
Option (D): The character pointer \texttt{c} pointing to the string literal \texttt{"abcd"} is valid, and the function calculates the length of the string correctly. Hence, Option (D) is correct. Final Answer: \[ \boxed{\text{(A), (B), (D)}} \]