Address and dereference operators in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the address of variable num.

C++

int num = 10;
int* ptr = [1]num;

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

A&

B*

C#

D%

Attempts:

3 left

💡 Hint

Common Mistakes

Using the dereference operator * instead of the address-of operator &.

Using symbols like # or % which are not related to pointers.

The address-of operator & is used to get the memory address of a variable.

2fill in blank

medium

Complete the code to access the value pointed to by ptr.

C++

int num = 20;
int* ptr = #
int value = [1]ptr;

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

A&

B%

C*

D->

Attempts:

3 left

💡 Hint

Common Mistakes

Using the address-of operator & instead of dereference operator *.

Using the arrow operator -> which is for pointers to structs or classes.

The dereference operator * is used to access the value stored at the memory address a pointer holds.

3fill in blank

hard

Fix the error in the code to correctly assign the value 50 to the variable pointed to by ptr.

C++

int num = 0;
int* ptr = #
[1]ptr = 50;

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

A*ptr

B&ptr

Cptr

Dptr*

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning directly to the pointer variable instead of the value it points to.

Using incorrect syntax like ptr* or &ptr.

To assign a value to the variable pointed to by a pointer, use the dereference operator * before the pointer name.

4fill in blank

hard

Fill both blanks to create a pointer ptr that points to num and then access its value.

C++

int num = 100;
int* ptr = [1]num;
int val = [2]ptr;

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

A&

B*

C->

D%

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the operators in the blanks.

Using the arrow operator -> which is not for simple pointers.

Use & to get the address of num and * to access the value pointed to by ptr.

5fill in blank

hard

Fill all three blanks to declare an integer num, a pointer ptr to num, and assign the value 75 to num using the pointer.

C++

int [1];
int* [2] = &[3];
*ptr = 75;

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

Anum

Bptr

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the variable and pointer inconsistently.

Not using the address-of operator & in the pointer initialization.

Declare num as the integer variable, ptr as a pointer to num, and use &num to get the address.