Pointer arithmetic 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] = &x;

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

Aptr

Bref

Cp

Dpointer

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that is a reserved keyword.

Forgetting the asterisk (*) to declare a pointer.

The pointer variable name can be any valid identifier. Here, 'p' is used as the pointer name.

2fill in blank

medium

Complete the code to increment the pointer to point to the next integer in memory.

C++

int arr[3] = {1, 2, 3};
int* p = arr;
p [1];

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

A--

B++

C+=

D-=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--' which moves the pointer backwards.

Using '+=' without a value.

Using '++' increments the pointer to the next integer in the array.

3fill in blank

hard

Fix the error in the code to correctly access the second element using pointer arithmetic.

C++

int arr[3] = {10, 20, 30};
int* p = arr;
int val = *(p [1] 1);

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

A+

B-

C/

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' which moves the pointer backwards.

Using '*' or '/' which are invalid for pointer arithmetic.

Adding 1 to the pointer moves it to the second element, then dereferencing gets its value.

4fill in blank

hard

Fill both blanks to create a pointer that points to the third element and then decrement it.

C++

int arr[4] = {5, 10, 15, 20};
int* p = arr [1] 2;
p [2];

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

A+

B-

C--

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' instead of '+' to move forward.

Using '++' instead of '--' to decrement.

Adding 2 moves pointer to third element; '--' decrements pointer to second element.

5fill in blank

hard

Fill all three blanks to create a pointer to the first element, move it forward by one, and then access the value.

C++

int arr[3] = {100, 200, 300};
int* [1] = arr;
[1] [2];
int val = *[3];

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

Ap

B++

Dq

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names for the pointer.

Forgetting to increment the pointer before dereferencing.

Pointer 'p' is declared, incremented, then dereferenced to get the second element's value.