PHP array sorting: an in-depth exploration from single dimension to multi-dimensional

PHP provides a wealth of array sorting functions, including sort(), rsort(), asort(), and arsort() for single-dimensional array sorting; for multi-dimensional array sorting, you can use the array_multisort() custom function. Sort in ascending or descending order by specifying multiple columns.

PHP Array Sorting: In-depth Exploration from Single Dimension to Multi-Dimension

Introduction

Array sorting is crucial in programming and can be used to organize and filter data. PHP provides several functions to sort arrays, including sort(), rsort(), asort(), arsort(), natsort(), natcasesort() etc.

Single-dimensional array sorting

Sorting a single-dimensional array is very simple, you can use the following function:

• sort( ): Sort array elements in ascending order.
• rsort(): Sort array elements in descending order.
• asort(): Sort in ascending order by key.
• arsort(): Sort in descending order by key.

Practical case: Sorting single-dimensional arrays of products in ascending order by name

<?php
$products = array(
    "Apple" => "iPhone",
    "Samsung" => "Galaxy",
    "Google" => "Pixel",
);

asort($products);

print_r($products);

Output:

Array
(
    [Apple] => iPhone
    [Google] => Pixel
    [Samsung] => Galaxy
)

Multi-dimensional array sorting

Sometimes, we need to sort multi-dimensional arrays. There is no out-of-the-box function in PHP to do this, but we can work around it with a custom function:

function array_multisort($array, $columns) {
    $temp = [];
    foreach($array as $k => $v) {
        $temp[$k] = [];
        foreach($columns as $key) {
            $temp[$k][$key] = $v[$key];
        }
    }
    array_multisort($temp, SORT_ASC);
    foreach($temp as $k => $v) {
        foreach($columns as $key) {
            $array[$k][$key] = $v[$key];
        }
    }
    return $array;
}

Practical example: Sorting multi-dimensional array by product name and price

<?php
$products = array(
    array(
        "name" => "iPhone",
        "price" => 1000,
    ),
    array(
        "name" => "Galaxy",
        "price" => 800,
    ),
    array(
        "name" => "Pixel",
        "price" => 900,
    ),
);

array_multisort($products, ['name', 'price']);

print_r($products);

Output:

Array
(
    [0] => Array
        (
            [name] => Galaxy
            [price] => 800
        )

    [1] => Array
        (
            [name] => iPhone
            [price] => 1000
        )

    [2] => Array
        (
            [name] => Pixel
            [price] => 900
        )
)

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