Summary - Arrays

Combine access and looping skills in a mini task.

In this group you learned what arrays are, how to access, iterate and update them. Array access and update are O(1).

Iterating all elements with a loop takes O(n) time. Linear search is also O(n) because every element is checked.

Exercise Print reverse

Write print_reverse(arr). Print elements from last to first with for. Call print_reverse([1, 2, 3]) to print 3, 2, 1.

Show example solution

def print_reverse(arr):
    # Print in reverse
    for i in range(len(arr) - 1, -1, -1):
        print(arr[i])
print_reverse([1, 2, 3])

Array index

In an array, elements are accessed by ____.

Show answer

In an array, elements are accessed by index.