Reverse an Array

Understanding Array Reversal

Reversing an array involves changing the order of elements so that the first element becomes the last and vice versa.

We will explore three different methods to reverse an array using Python.

Method 1: Using Slicing

This method uses Python's slicing feature to reverse the array.

def reverse_array(arr):
    return arr[::-1]

arr = [1, 2, 3, 4, 5]
print(reverse_array(arr))
            

Method 2: Using Recursion

This method reverses the array using a recursive function.

def reverse_recursive(arr, start, end):
    if start >= end:
        return
    arr[start], arr[end] = arr[end], arr[start]
    reverse_recursive(arr, start + 1, end - 1)

arr = [1, 2, 3, 4, 5]
reverse_recursive(arr, 0, len(arr) - 1)
print(arr)
            

Method 3: Using a Second List

This method stores the reversed elements in a new list.

def reverse_new_list(arr):
    rev_arr = []
    for i in range(len(arr) - 1, -1, -1):
        rev_arr.append(arr[i])
    return rev_arr

arr = [1, 2, 3, 4, 5]
print(reverse_new_list(arr))