Sorting Multidimensional Arrays in PHP: A Versatile Solution

This comprehensive guide addresses the task of sorting multidimensional arrays in PHP. It offers a reusable and highly customizable solution that empowers you with the ability to sort your data effortlessly.

The Solution: make_comparer() Function

function make_comparer() {
    // Normalize criteria up front
    $criteria = func_get_args();
    foreach ($criteria as $index => $criterion) {
        $criteria[$index] = is_array($criterion)
            ? array_pad($criterion, 3, null)
            : array($criterion, SORT_ASC, null);
    }

    return function($first, $second) use (&$criteria) {
        foreach ($criteria as $criterion) {
            // Determine sort criteria
            list($column, $sortOrder, $projection) = $criterion;
            $sortOrder = $sortOrder === SORT_DESC ? -1 : 1;

            // Project values if necessary
            if ($projection) {
                $lhs = call_user_func($projection, $first[$column]);
                $rhs = call_user_func($projection, $second[$column]);
            } else {
                $lhs = $first[$column];
                $rhs = $second[$column];
            }

            // Compare values; do not return if equal
            if ($lhs < $rhs) {
                return -1 * $sortOrder;
            } elseif ($lhs > $rhs) {
                return 1 * $sortOrder;
            }
        }

        return 0; // tiebreakers exhausted, so $first == $second
    };
}

How to Use

Basic Usage: Sorting by a Single Column

// Sort $data by the "name" column using uasort
$data = array(
    array('zz', 'name' => 'Jack', 'number' => 22, 'birthday' => '12/03/1980'),
    array('xx', 'name' => 'Adam', 'number' => 16, 'birthday' => '01/12/1979'),
    array('aa', 'name' => 'Paul', 'number' => 16, 'birthday' => '03/11/1987'),
    array('cc', 'name' => 'Helen', 'number' => 44, 'birthday' => '24/06/1967'),
);
uasort($data, make_comparer('name'));

Sorting by Multiple Columns:

// Sort $data by "number" and then by the zero-indexed column (ID)
uasort($data, make_comparer('number', 0));

Advanced Features

Reverse Sorting:

// Sort $data by "name" descending
uasort($data, make_comparer(['name', SORT_DESC]));

Custom Projections:

// Sort $data by "birthday" using date_create as a projection
uasort($data, make_comparer(['birthday', SORT_ASC, 'date_create']));

Combining Features:

// Sort $data by "number" descending and then by "birthday" ascending
uasort($data, make_comparer(
    ['number', SORT_DESC],
    ['birthday', SORT_ASC, 'date_create']
));

Conclusion

This solution provides a wide range of capabilities to sort multidimensional arrays in PHP. Its flexibility and ease of use make it a powerful tool for data manipulation in various scenarios.

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