Bubble Sort in PHP

<?php

class BubbleSort {

   public static function sort(&$arr) {
       $size = count($arr);

       for($i = 0; $i < $size - 1; $i++) {
           // For each element, loop over and find inversions.
           for($j = 0; $j < $size - $i - 1; $j++) {
               // If i and j are inverted, swap them
               if($arr[$j] > $arr[$j + 1]) {
                   BubbleSort::swap($arr, $j, $j + 1);
               }
           }
       }
   }

   public static function sortFaster(&$arr) {

       $size = count($arr);
       
       for($i = 0; $i < $size - 1; $i++) {
           // Set swapped flag to false.
           $swapped = false;
           // For each element, loop over and find inversions.
           for($j = 0; $j < $size - $i - 1; $j++) {
               // If i and j are inverted, swap them
               if($arr[$j] > $arr[$j + 1]) {
                   BubbleSort::swap($arr, $j, $j + 1);
                   // set the swap flag to true.
                   $swapped = true;
               }
           }
           // Check for any swaps
           if(!$swapped) {
               // If not, we are done.
               break;
           }
       }
   }

   public static function swap(&$arr, $a, $b) {
       $tmp = $arr[$a];
       $arr[$a] = $arr[$b];
       $arr[$b] = $tmp;
   }
}