Pointers and arrays in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a pointer in C++?

A pointer is a variable that stores the memory address of another variable. It 'points' to the location where data is stored.

beginner

How are arrays and pointers related in C++?

The name of an array acts like a pointer to its first element. You can use pointers to access array elements by moving through memory addresses.

intermediate

What does the expression *(arr + i) mean?

It means accessing the element at index i of the array arr by moving i positions from the start address and dereferencing the pointer.

beginner

How do you declare a pointer to an integer in C++?

You declare it like this: int* ptr; where ptr can store the address of an integer variable.

intermediate

What happens if you increment a pointer pointing to an array element?

Incrementing the pointer moves it to the next element in the array, because it increases the address by the size of the element type.

What does the pointer variable store?

A Size of a variable

B Value of another variable

C Type of a variable

D Memory address of another variable

Pointers store the memory address where data is located, not the data itself.

If int arr[5];, what does arr represent?

A Pointer to the last element of arr

B Pointer to the first element of arr

C Value of the first element

D Size of the array

The array name acts as a pointer to its first element.

What does *(arr + 2) access?

A Third element of arr

B Second element of arr

C First element of arr

D Fourth element of arr

Pointer arithmetic moves by element size, so adding 2 moves to the third element (index 2).

How do you declare a pointer to a float variable?

A float* ptr;

B ptr* float;

C float ptr*;

D pointer float ptr;

The correct syntax is float* ptr;.

What happens when you do ptr++ if ptr points to an int array element?

A Pointer value stays the same

B Pointer moves to the next byte

C Pointer moves to the next int element

D Pointer moves to the previous element

Incrementing a pointer moves it by the size of the type it points to, so to the next int element.

Explain how pointers and arrays are connected in C++.

Think about how the array name can be used like a pointer to the first element.

Describe what happens when you increment a pointer that points to an array element.

Consider how memory addresses change when moving through an array.