What is the purpose of the array_multisort function in PHP?

The array_multisort function is used to sort multiple arrays or multidimensional arrays. It can sort based on the values of one or more arrays, and allows for specifying the sorting method and order. It is commonly used for sorting data, such as sorting database query results or sorting multidimensional arrays based on a specific field.

The array_multisort function can accept multiple parameters, each of which is an array that can be sorted. The sorting rule is to first sort by the values of the first array, then by the values of the second array if the values are the same, and so on. The sorting method and order can be specified through parameters, such as ascending or descending order.

Here is an example code:

$names = array("John", "Will", "Alice");
$ages = array(20, 30, 25);
array_multisort($names, $ages);

print_r($names);  // 输出：Array ( [0] => Alice [1] => John [2] => Will )
print_r($ages);   // 输出：Array ( [0] => 25 [1] => 20 [2] => 30 )

In this example, the values in the $names array are sorted first, followed by the values in the $ages array. The final result is sorting the $names and $ages arrays according to their respective orders.