What is an array?

Learn that an array stores same-type elements in contiguous memory.

An array is a data structure where elements of the same type are stored contiguously in memory. Each element has an index and access is O(1).

Indices start at 0: the first element is arr[0], the second arr[1]. The length is obtained with len(arr).

Array access

To access an element, write arr[index]. Access takes O(1) time because the address is computed directly.

An invalid index raises an error. For example, accessing arr[5] in a 3-element array raises an out-of-bounds error.

Write get_element(arr, i). Return arr[i]. Print 20 with print(get_element([10, 20, 30], 1)).

Show example solution

def get_element(arr, i):
    # Return element
    return arr[i]
print(get_element([10, 20, 30], 1))

Array access

To access the third element: arr[____]

Show answer

To access the third element: arr[2]

Next lesson: Array access