PHP Exercises: Sort a collection of given arrays or objects by key

PHP: Exercise-93 with Solution

Write a PHP program to sort a collection of given arrays or objects by key.

Sample Solution:

PHP Code:

<?php
// Licence: https://bit.ly/2CFA5XY

// Function definition for 'orderBy' that takes an array of items, an attribute, and an order ('asc' or 'desc') as parameters
function orderBy($items, $attr, $order)
{
    // Initialize an empty associative array to store the items with keys based on the specified attribute
    $sortedItems = [];

    // Iterate through each item in the array
    foreach ($items as $item) {
        // Determine the key based on whether the item is an object or an array
        $key = is_object($item) ? $item->{$attr} : $item[$attr];

        // Assign the item to the associative array using the calculated key
        $sortedItems[$key] = $item;
    }

    // Check if the order is 'desc' and use 'krsort' to sort the array in descending order based on keys
    // If the order is not 'desc', use 'ksort' to sort the array in ascending order based on keys
    if ($order === 'desc') {
        krsort($sortedItems);
    } else {
        ksort($sortedItems);
    }

    // Use 'array_values' to reindex the array after sorting
    return array_values($sortedItems);
}

// Call 'orderBy' with an array of associative arrays, an attribute ('id'), and an order ('desc')
// Display the result using 'print_r'
print_r(orderBy(
    [
        ['id' => 2, 'name' => 'Red'],
        ['id' => 3, 'name' => 'Black'],
        ['id' => 1, 'name' => 'Green']
    ],
    'id',
    'desc'
));
?>

Sample Output:

Array
(
    [0] => Array
        (
            [id] => 3
            [name] => Black
        )

    [1] => Array
        (
            [id] => 2
            [name] => Red
        )

    [2] => Array
        (
            [id] => 1
            [name] => Green
        )

)

Flowchart:

PHP Code Editor:

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