Selection Sort in PHP

<?php

class SelectionSort {
   public static function sort(&$arr) {
       $arrLen = count($arr);
       // Iterate over the entire array, except the last element (0...n-1).
       for($i = 0; $i < $arrLen; $i++) {
           $min = $i;
           // Iterate the remaining array (i...n).
           for($j = $i + 1; $j < $arrLen; $j++) {
               // If j is less than the min, update the min index.
               if($arr[$j] < $arr[$min]) {
                   $min = $j;
               }
           }
           // Do an in place swap.
           $tmp = $arr[$min];
           $arr[$min] = $arr[$i];
           $arr[$i] = $tmp;
       }
   }
}