How to Use PHP’s array_multisort() Function to Sort Multiple Arrays

In the PHP function library, the array_multisort() function is a powerful tool that can sort multiple arrays according to specified criteria. This article introduces how to use array_multisort().

1. Syntax of array_multisort()

array_multisort ( array &$array1 [, mixed $array1_sort_order = SORT_ASC [, mixed $array1_sort_flags = SORT_REGULAR [, mixed $... [, mixed $... ]]]]) : bool

Parameter description:

1. &$array1: Required array to be sorted.

2. $array1_sort_order: Optional sorting order for the first array (SORT_ASC, SORT_DESC, or default).

3. $array1_sort_flags: Optional sorting type for the first array (SORT_REGULAR, SORT_NUMERIC, SORT_STRING).

4. $... : Optional additional arrays to be sorted.

2. Example Demonstration of array_multisort() Usage

Assume we want to sort the "name" and "age" arrays based on the students' "score" array. The following code shows how to achieve this:

$names = array('Tom', 'Jack', 'Mike', 'John');
$ages = array('25', '18', '20', '22');
$scores = array('80', '60', '70', '90');
array_multisort($scores, SORT_DESC, SORT_NUMERIC, $names, $ages);

The code defines three arrays ($names, $ages, $scores) and then calls array_multisort() to sort $scores in descending numeric order while reordering $names and $ages to match the new order.

Note that the SORT_NUMERIC flag specifies that $scores should be treated as numeric values.

3. Execution Result

Running the code produces the following arrays:

Array
(
    [0] => John
    [1] => Tom
    [2] => Mike
    [3] => Jack
)
Array
(
    [0] => 22
    [1] => 25
    [2] => 20
    [3] => 18
)

The $scores array is sorted as 90, 80, 70, 60, and the corresponding names and ages are John (22), Tom (25), Mike (20), and Jack (18).

Conclusion

The array_multisort() function is a convenient way to sort multiple arrays simultaneously, improving efficiency in PHP development. Proper use of its parameters is essential to avoid errors.