Array slice reverse array

We can use slicing to reverse an array. The steps are as follows: Define an array containing elements in reverse order. Use the slice assignment operation to assign the reversed elements back to the original array.

Array slice reverses an array

In programming, an array slice is a contiguous subsection of an array. We can use slicing to reverse an array, that is, change the order of the elements in the array so that they are arranged from back to front. There are many ways to implement array slice reversal. Here is one method using slice assignment:

1. Syntax

array[start:end:step] = reversed_array

Among them:

• array: The array to be reversed.
• start: The starting index of the slice (optional, default is 0).
• end: The end index of the slice (optional, defaults to the length of the array).
• step: Step size between elements in the slice (optional, default is 1).
• reversed_array: An array containing elements in reversed order.

2. Practical case

Consider the following array:

array = [1, 2, 3, 4, 5]

Using the above syntax, we can reverse the array like this:

# 定义一个包含反转顺序元素的数组
reversed_array = array[::-1]

# 将反转后的元素赋值回原数组
array[0:] = reversed_array

After executing this code, the array array will be reversed to:

print(array)  # 输出：[5, 4, 3, 2, 1]

Note:

• Use slice inversion is a temporary array, so its time complexity is O(n), where n is the length of the array.
• The slice assignment operation modifies the original array without explicitly returning the reversed array.

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