How to ensure the uniqueness of elements after the PHP array is shuffled?

The methods in PHP to disrupt the order of an array to ensure the uniqueness of elements are: use the array_unique() function: first disrupt the order, and then remove duplicate elements. Use the array_diff() function: find the difference between two arrays, removing elements that are the same as the other array.

How to ensure the uniqueness of elements after shuffling the order of a PHP array

In PHP, shuffling the order of the array will destroy the elements order, but the uniqueness of the elements cannot be guaranteed. If you need an array with unique elements and the order is scrambled, you can use the following method:

Method 1: Use array_unique()Function

array_unique()The function can remove duplicate elements from an array but retain the original order of the elements. Therefore, you can first disrupt the order of the array, and then use the array_unique() function to remove duplicate elements:

<?php
$array = [1, 2, 3, 4, 5, 1, 2, 3];

// 打乱数组顺序
shuffle($array);

// 去除重复元素
$unique_array = array_unique($array);

print_r($unique_array);
?>

Method 2: Use the array_diff() function

array_diff()The function can find the difference between two or more arrays, that is, return the elements in the first array that do not exist in other arrays. You can use this feature to remove elements from one array that are the same as another array:

<?php
$array1 = [1, 2, 3, 4, 5, 1, 2, 3];
$array2 = [2, 3, 4];

// 打乱数组1的顺序
shuffle($array1);

// 求出array1中不存在于array2中的元素
$unique_elements = array_diff($array1, $array2);

print_r($unique_elements);
?>

Practical Case

Suppose there is an array containing user IDs that need to be randomized Sort and ensure the uniqueness of each user ID. You can use the following code:

<?php
$user_ids = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

// 打乱用户ID的顺序
shuffle($user_ids);

// 去除重复的用户ID
$unique_user_ids = array_unique($user_ids);

// 输出随机排序的唯一用户ID
print_r($unique_user_ids);
?>

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