php从数组中随机选择若干唯一元素

<?php  /*   * $array = the array to be filtered   * $total = the maximum number of items to return   * $unique = whether or not to remove duplicates before getting a random list   */  function unique_array($array, $total, $unique = true){      $newArray = array();      if((bool)$unique){          $array = array_unique($array);      }      shuffle($array);      $length = count($array);      for($i = 0; $i < $total; $i++){          if($i < $length){              $newArray[] = $array[$i];          }      }      return $newArray;  }     $phrases = array('Hello Sailor','Acid Test','Bear Garden','Botch A Job','Dark Horse',      'In The Red','Man Up','Pan Out','Quid Pro Quo','Rub It In','Turncoat',      'Yes Man','All Wet','Bag Lady','Bean Feast','Big Wig', 'Big Wig','Bear Garden'      ,'All Wet','Quid Pro Quo','Rub It In');     print_r(unique_array($phrases, 1));             // Returns 1 result  print_r(unique_array($phrases, 5));             // Returns 5 unique results  print_r(unique_array($phrases, 5, false));      // Returns 5 results, but may have duplicates if                                                  // there are duplicates in original array  print_r(unique_array($phrases, 100));           // Returns 100 unique results      print_r(unique_array($phrases, 100, false));    // Returns 100 results, but may have duplicates if                                                  // there are duplicates in original array