Structure and Union MCQs

Question 1

When should you use a structure instead of an array in C?

Accepted Answer

When you need to store elements of different data types

Answer

When you need a fixed-size collection of elements

Answer

When you need a dynamic collection of elements

Answer

When you need to perform mathematical operations

Question 2

What is the purpose of an anonymous union in C?

Accepted Answer

To declare a union without a name

Answer

To group related members within a structure

Answer

To hide the union's members from external access

Answer

To specify a union's memory alignment

Question 3

Which keyword is used to access a member of a nested structure in C?

Accepted Answer

. (dot)

Answer

-> (arrow)

Answer

:: (scope)

Answer

, (comma)

Question 4

What is the main advantage of using a union in C?

Accepted Answer

It saves memory by sharing the same memory location

Answer

It allows easy access to all members

Answer

It enforces strong data typing

Answer

It prevents data from being modified

Question 5

What is the size of an empty structure in C?

Accepted Answer

0 bytes

Answer

1 byte

Answer

It varies depending on the compiler

Answer

4 bytes

Question 6

In C, can you compare two structures using the equality operator (==)?

Accepted Answer

No, never

Answer

Yes, always

Answer

Only if both structures have the same name

Answer

Only if both structures have the same members

Question 7

What is the primary use of a union in a C program?

Accepted Answer

To represent multiple data types using the same memory location

Answer

To store a collection of elements of the same type

Answer

To organize data into a hierarchy

Answer

To define a custom data type

Question 8

How do you declare an array of structures in C?

Accepted Answer

myStruct array[];

Answer

struct myStruct arr[];

Answer

struct array myStruct[];

Answer

myStruct[] arr;

Question 9

Which of the following is not a valid type for a structure member in C?

Accepted Answer

Function

Answer

Array

Answer

Pointer

Answer

Enumeration