How to Sort Multidimensional Arrays in PHP Using a Flexible and Reusable Function?

How to Sort a Multidimensional Array in PHP

Introducing a Generalized Solution for PHP 5.3

Implementation:

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 $criterion) {
            list($column, $sortOrder, $projection) = $criterion;
            $sortOrder = $sortOrder === SORT_DESC ? -1 : 1;

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

            if ($lhs < $rhs) {
                return -1 * $sortOrder;
            } elseif ($lhs > $rhs) {
                return 1 * $sortOrder;
            }
        }

        return 0; // tiebreakers exhausted
    };
}

Advanced Features:

(1) Multiple Sort Columns:

usort($data, make_comparer('number', 'name'));

(2) Reverse Sort:

usort($data, make_comparer(['name', SORT_DESC]));

(3) Custom Projections:

usort($data, make_comparer(['birthday', SORT_ASC, 'date_create']));

(4) Combining Features:

usort($data, make_comparer(
    ['number', SORT_DESC],
    ['birthday', SORT_ASC, 'date_create']
));

Benefits:

• Reusable
• Flexible
• Reversible
• Extensible
• Associative

The above is the detailed content of How to Sort Multidimensional Arrays in PHP Using a Flexible and Reusable Function?. For more information, please follow other related articles on the PHP Chinese website!