Pointer and variable relationship in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a pointer to an integer variable.

C++

int x = 10;
int [1] ptr = &x;

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

A*

B&

C#

D%

Attempts:

3 left

💡 Hint

Common Mistakes

Using & instead of * when declaring a pointer.

Confusing pointer declaration with address-of operator.

The asterisk (*) is used to declare a pointer variable in C++.

2fill in blank

medium

Complete the code to assign the address of variable x to pointer ptr.

C++

int x = 5;
int* ptr;
ptr = [1]x;

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

A*

B&&

C%

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using * instead of & when assigning address.

Using && which is for rvalue references, not addresses.

The ampersand (&) operator gives the address of a variable.

3fill in blank

hard

Fix the error in the code to correctly print the value pointed to by ptr.

C++

int x = 20;
int* ptr = &x;
std::cout << [1]ptr << std::endl;

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

A&ptr

Bptr

C*ptr

D&&ptr

Attempts:

3 left

💡 Hint

Common Mistakes

Printing the pointer itself instead of the value it points to.

Using &ptr which gives the address of the pointer variable, not the value.

Using *ptr dereferences the pointer to get the value it points to.

4fill in blank

hard

Fill both blanks to declare a pointer and assign it the address of variable y.

C++

int y = 15;
[1] ptr = [2]y;

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

Aint*

Bint

C&

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using int instead of int* for pointer declaration.

Using *y instead of &y when assigning address.

int* declares a pointer to int, and &y gets the address of y.

5fill in blank

hard

Fill all three blanks to declare a pointer, assign it the address of z, and print the value pointed to by ptr.

C++

int z = 30;
[1] ptr = [2]z;
std::cout << [3]ptr << std::endl;

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

Aint*

B&

C*

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Using int instead of int* for pointer declaration.

Assigning *z instead of &z.

Printing ptr instead of *ptr.

int* declares the pointer, &z gets the address, and *ptr dereferences to the value.