Memory Allocation MCQs

Question 1

How do you check if the 'realloc' function has successfully reallocated memory in C?

Accepted Answer

Check if the return value is not NULL

Answer

Check if the return value is 1

Answer

Check if the return value is -1

Answer

Check if the return value is 0

Question 2

Which function is used to free allocated memory but does not remove the pointer in C?

Accepted Answer

free()

Answer

clear()

Answer

release()

Answer

deallocate()

Question 3

What is the maximum number of bytes that can be allocated using 'malloc' in C?

Accepted Answer

It depends on the system and available memory

Answer

2^16 bytes

Answer

2^32 bytes

Answer

2^64 bytes

Question 4

What is the difference between 'malloc' and 'calloc' in C?

Accepted Answer

'malloc' allocates uninitialized memory, 'calloc' allocates and initializes to zero

Answer

'malloc' allocates and initializes to zero, 'calloc' allocates uninitialized memory

Answer

'malloc' is used for arrays, 'calloc' is used for single elements

Answer

'malloc' allocates memory from the stack, 'calloc' allocates from the heap

Question 5

In C, which function is used to allocate memory from the stack?

Accepted Answer

malloc()

Answer

alloc()

Answer

stackalloc()

Answer

calloc()

Question 6

What happens if you attempt to free the same block of memory twice in C?

Accepted Answer

It leads to undefined behavior

Answer

The program terminates

Answer

Memory is released, but the pointer remains valid

Answer

Memory is leaked

Question 7

What is the primary advantage of using dynamic memory allocation in C?

Accepted Answer

Flexibility to allocate memory at runtime

Answer

Faster execution of programs

Answer

Smaller memory footprint

Answer

Elimination of memory leaks

Question 8

Which function is used to allocate memory for a structure in C?

Accepted Answer

malloc()

Answer

structurealloc()

Answer

structalloc()

Answer

calloc()

Question 9

What is the difference between 'free' and 'delete' in C?

Accepted Answer

'free' is used for dynamic memory, 'delete' is used for static memory

Answer

'free' is used for dynamic memory, 'delete' is used for freeing memory

Answer

'free' is used for C, 'delete' is used for C++

Answer

'free' is used for static memory, 'delete' is used for dynamic memory