Consider the following C function definition. int fX(char *a){ char *b = a;…

Answer: The following statements are true:

• The function call fX(”abcd”) will always return a value

• Assuming a character array c is declared as char c[] = ”abcd” in main(), the function call fX(c) will always return a value

• Assuming a character pointer c is declared as char *c = ”abcd” in main(), the function call fX(c) will always return a value

Reason:

• The function sets b to a and advances b while *b is non-zero; the loop stops when b points to the terminating null character '\0'.

• When the loop ends, b points at the terminating null, so the expression b - a yields the number of characters before the null (the string length).

• All three provided inputs are null-terminated strings, so the function returns 4 for these examples.

• The code compiles in C: pointer arithmetic and the while(*b) check are valid. The claim that the code will not compile is false.

• Note: Modifying a string literal is undefined behavior. This function does not modify the string, so passing a string literal to a function accepting char* is safe in C (though best practice is to use const char* if modification is not intended).

Concrete result: For the examples given, the function returns 4.