How to Sort a Multidimensional PHP Array by Multiple Fields?

Sorting an Array by Multiple Field Values in PHP

Problem:

You have an array with complex data structures, and you need to sort the values based on multiple field values in ascending order.

Example:

Consider the following array:

$array = [
    [
        "destination" => "Sydney",
        "airlines" => "airline_1",
        "one_way_fare" => 100,
        "return_fare" => 300
    ],
    [
        "destination" => "Sydney",
        "airlines" => "airline_2",
        "one_way_fare" => 150,
        "return_fare" => 350
    ],
    [
        "destination" => "Sydney",
        "airlines" => "airline_3",
        "one_way_fare" => 180,
        "return_fare" => 380
    ]
];

You want to sort this array by first "return_fare" in ascending order and then by "one_way_fare" also in ascending order.

Solution:

To sort the array as described, you can use the array_multisort() function. However, it requires you to extract the values you want to sort into separate arrays. This can be done using array_column().

// Extract "return_fare" and "one_way_fare" into separate arrays
$return_fare = array_column($array, 'return_fare');
$one_way_fare = array_column($array, 'one_way_fare');

// Sort the array using multiple criteria
array_multisort($return_fare, SORT_ASC, $one_way_fare, SORT_ASC, $array);

After sorting, the $array will be modified to reflect the sorted order.

Alternative Solution:

You can also use the array_orderby() function from PHP's manual page to simplify the above code:

// Sort the array using "array_orderby"
$sorted = array_orderby($array, 'return_fare', SORT_ASC, 'one_way_fare', SORT_ASC);

Note:

If you are using PHP 5.5 or higher, you can avoid the looping by using array_column() directly with array_multisort():

array_multisort(
    array_column($array, 'return_fare'), SORT_ASC,
    array_column($array, 'one_way_fare'), SORT_ASC,
    $array
);

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