PHP Selection Sort O(n^2)

selection-sort.php

<?php
// O(n^2)
function selectionSort( array $array ) {
    $length = count($array);

    for ( $i = 0; $i < $length; $i++) {
        $min = $i;

        for( $j = $i + 1; $j < $length; $j++ ) {
            if ( $array[$min] > $array[$j] )
                $min = $j;
        }

        $temp = $array[$i];
        $array[$i] = $array[$min];
        $array[$min] = $temp;
    }

    return $array;
}