Memory allocation and deallocation in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to allocate memory for an integer using new.

C++

int* ptr = [1] int;

Drag options to blanks, or click blank then click option'

Amalloc

Bnew

Calloc

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using malloc instead of new in C++.

Forgetting to use new keyword.

In C++, new is used to allocate memory dynamically.

2fill in blank

medium

Complete the code to deallocate memory allocated for an integer pointer.

C++

delete [1];

Drag options to blanks, or click blank then click option'

A*ptr

Bptr()

Cptr

D&ptr

Attempts:

3 left

💡 Hint

Common Mistakes

Using *ptr instead of ptr in delete.

Using ptr() which is invalid syntax.

Use delete followed by the pointer variable to free memory.

3fill in blank

hard

Fix the error in the code to allocate an array of 5 integers.

C++

int* arr = [1] int[5];

Drag options to blanks, or click blank then click option'

Anew

Bmalloc

Calloc

Dnew[]

Attempts:

3 left

💡 Hint

Common Mistakes

Using malloc instead of new.

Writing new[] without the type.

Use new with square brackets to allocate arrays: new int[5].

4fill in blank

hard

Fill both blanks to correctly deallocate the array allocated with new.

C++

delete[1] [2];

Drag options to blanks, or click blank then click option'

A[]

B()

Cptr

Dptr[]

Attempts:

3 left

💡 Hint

Common Mistakes

Using delete without brackets for arrays.

Using parentheses instead of brackets.

Use delete[] followed by the pointer to free arrays allocated with new[].

5fill in blank

hard

Fill all three blanks to allocate memory for a double, assign a value, and then deallocate it.

C++

double* [1] = [2] double;
*[1] = 3.14;
delete [3];
[1] = nullptr;

Drag options to blanks, or click blank then click option'

Aptr

Bnew

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Forgetting to delete the allocated memory.

First declare pointer ptr, allocate with new, assign value, then delete ptr.