Structures, Unions, Enums Questions and Answers

Answer: A

Correct answer: Error, though the code this depends on is missing

The program listing this question asks about is absent from the record - only the words “What will be output for the following code?” survive, with nothing following them. The four options are “Error”, 5, 6 and 2, and the item is keyed to “Error”, so the original code presumably contained a mistake the compiler would reject. Which mistake cannot be recovered from what remains. The topic is structures, unions and enumerations, where the commonest sources of a compile error are using the dot operator on a pointer to a structure instead of ->, omitting the tag or the semicolon that must follow a struct definition, assigning to an enumeration constant, or taking sizeof an incomplete type. The item needs its listing restored before it can be worked.

Answer: B

In the code shown above, the value of example1 is returned by the function answer. The ternary statement prints yes if this value is equal to that of ‘a’ and no if the value is not equal to that of ‘a’. Since the value of ‘a’ is 1 and that returned by the function is 2, therefore no is printed.

Answer: D

Correct answer: Error

An enumerator’s value must be an integer constant expression. b = 3.56 is a floating-point constant, so the declaration is rejected. Enumerations are a way of naming integers, and nothing else.

Answer: D

Correct answer: 0

Unless told otherwise the compiler starts at 0 and adds one for each following enumerator. Where a value is given explicitly, counting resumes from there - so {a, b = 5, c} gives 0, 5, 6.