Why dynamic memory is needed in C++ - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to allocate an integer dynamically.

C++

int* ptr = [1] int;

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

Aauto

Bmalloc

Cdelete

Dnew

Attempts:

3 left

💡 Hint

Common Mistakes

Using malloc instead of new in C++.

Using delete to allocate memory.

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

2fill in blank

medium

Complete the code to free the dynamically allocated memory.

C++

delete [1];

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

Aptr

B*ptr

Cptr()

D&ptr

Attempts:

3 left

💡 Hint

Common Mistakes

Using delete *ptr which deletes the value, not the memory.

Using delete ptr() which is invalid syntax.

To free memory allocated with new, use delete followed by the pointer variable.

3fill in blank

hard

Fix the error in the code to allocate an array dynamically.

C++

int* arr = new int[1]10;

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

A{}

B()

C[]

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of square brackets for array size.

Using angle brackets which are for templates.

To allocate an array dynamically, use square brackets [] with the size.

4fill in blank

hard

Fill both blanks to create a dynamic array and delete it properly.

C++

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

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

A[]

Bdelete[]

Cdelete

D()

Attempts:

3 left

💡 Hint

Common Mistakes

Using delete instead of delete[] for arrays.

Using parentheses instead of square brackets for allocation.

Use [] to allocate an array and delete[] to free it.

5fill in blank

hard

Fill all three blanks to allocate, use, and free dynamic memory correctly.

C++

int* [1] = new int[2]3;
[1][0] = 10;
[3] [1];

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

Aarr

B[]

Cdelete[]

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using delete instead of delete[] for arrays.

Inconsistent pointer variable names.

Declare pointer arr, allocate array with [], and free with delete[].