How to disrupt the order of array elements in php

In PHP, we often need to operate arrays. One of the more common needs is to disrupt the order of array elements. Shuffling the order of the array can be achieved using PHP's built-in function shuffle(), which can randomly shuffle the order of the elements of the array.

The following will briefly introduce how to use the PHP function shuffle().

1. The syntax of the shuffle() function

The syntax of the shuffle() function is as follows:

shuffle ( array &$array ) : bool

Among them, $array means the array to be shuffled, & means passing Array reference, the function directly operates on the array.

This function returns a Boolean value indicating whether the order of the array was successfully disrupted, where true indicates success and false indicates failure.

2. Usage of shuffle() function

The following is an example of using the shuffle() function to disrupt the order of array elements:

<?php // 定义一个数组
$array = array("a", "b", "c", "d", "e");

// 打乱数组的顺序
shuffle($array);

// 输出打乱后的数组
print_r($array);
?>

In this example, first define a Array $array, which contains 5 elements, then use the shuffle() function to shuffle the array, and finally use the print_r() function to output the shuffled array to the page.

Run the above example, the output may be as follows:

Array
(
    [0] => d
    [1] => a
    [2] => b
    [3] => e
    [4] => c
)

You can see that the order of the scrambled array is different from the order of the original array.

3. Notes

You need to pay attention to the following points when using the shuffle() function to disrupt the order of the array:

1. The shuffle() function can only be used Scrambling index arrays cannot be used for associative arrays. If you want to scramble an associative array, you need to convert it to an index array first.
2. The shuffle() function directly operates on the original array, so the array passed to the function must be passed by reference, and the & symbol must be added before the array name when used.
3. The Boolean value returned by the shuffle() function indicates whether the order of the array has been successfully shuffled, but it is not always necessary to check this value, because even if the shuffling fails, the order of the original array will not change.

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