<?php class Bubble {   private function __construct() {   }   private static function sortt($data) {     if (count ( $data ) <= 1) {      return $data;     }     $tem = $data [0]['score'];     $leftarray = array ();     $rightarray = array ();     for($i = 1; $i < count ( $data ); $i ++) {       if ($data [$i]['score'] <= $tem ) {         $leftarray[] = $data[$i];       } else {         $rightarray[] = $data[$i];       }     }     $leftarray=self::sortt($leftarray);     $rightarray=self::sortt($rightarray);     $sortarray = array_merge ( $leftarray, array ($data[0]), $rightarray );     return $sortarray;   }   public static function main($data) {     $ardata = self::sortt ( $data );     return $ardata;   } }  $arr=array(   array('sid'=>1,'score'=>76),   array('sid'=>2,'score'=>93),   array('sid'=>3,'score'=>68.5),   array('sid'=>4,'score'=>82.5),   array('sid'=>5,'score'=>60.5) ); print_r(Bubble::main($arr));