Structure and Union MCQs

Question 1

Can a structure have another structure as a member in C?

Accepted Answer

Yes, without any limitations

Answer

No, it's not allowed

Answer

Yes, but with a limited depth

Answer

Only if the inner structure is named "Inner"

Question 2

Which operator is used to access a union member when the union is a part of a structure?

Accepted Answer

. (dot)

Answer

-> (arrow)

Answer

:: (scope)

Answer

, (comma)

Question 3

What happens when you assign a value to one member of a union and then access another member in C?

Accepted Answer

It leads to undefined behavior

Answer

It's allowed and safe

Answer

It raises a compilation error

Answer

It swaps the values of both members

Question 4

Which keyword is used to define an anonymous structure or union within another structure or union?

Accepted Answer

struct

Answer

anonymous

Answer

hidden

Answer

none of the above

Question 5

In a union, which member can you access safely after assigning a value to one of its members?

Accepted Answer

Only the first assigned member

Answer

All members can be accessed

Answer

Only the last assigned member

Answer

Any member, but it's compiler-dependent

Question 6

Which type of variable should you use if you want to store different types of data at different times within the same memory location?

Accepted Answer

union

Answer

int

Answer

float

Answer

char

Question 7

Which of the following is true about the memory allocation of structures and unions in C?

Accepted Answer

Structures allocate memory for the largest member

Answer

Structures require memory for all members simultaneously

Answer

Unions require memory for all members simultaneously

Answer

Unions allocate memory for the smallest member

Question 8

In C, can a structure be passed as an argument to a function?

Accepted Answer

Yes, by reference

Answer

Yes, by value

Answer

No, it's not allowed

Answer

Only if the structure has fewer than 3 members

Question 9

What is the purpose of using a typedef with structures and unions in C?

Accepted Answer

To create a new data type name for the structure or union

Answer

To create a new structure with the same members

Answer

To hide the details of the structure or union

Answer

To add typecasting support to the structure or union