function get_gift(){ 
  //拼装奖项数组 
  // 奖项id，奖品，概率
  $prize_arr = array( 
   '0' => array('id'=>1,'prize'=>'平板电脑','v'=>0), 
   '1' => array('id'=>2,'prize'=>'数码相机','v'=>0), 
   '2' => array('id'=>3,'prize'=>'音箱设备','v'=>0), 
   '3' => array('id'=>4,'prize'=>'4G优盘','v'=>5), 
   '4' => array('id'=>5,'prize'=>'10Q币','v'=>0), 
   '5' => array('id'=>6,'prize'=>'空奖','v'=>5), 
  ); 
  foreach ($prize_arr as $key => $val) { 
   $arr[$val['id']] = $val['v'];//概率数组 
  } 
  $rid = $this->get_rand($arr); //根据概率获取奖项id 
  $res['yes'] = $prize_arr[$rid-1]['prize']; //中奖项 
  unset($prize_arr[$rid-1]); //将中奖项从数组中剔除，剩下未中奖项 
  shuffle($prize_arr); //打乱数组顺序 
  for($i=0;$i<count($prize_arr);$i++){ 
   $pr[] = $prize_arr[$i]['prize']; //未中奖项数组 
  } 
  $res['no'] = $pr; 
  // var_dump($res);

   
  if($res['yes']!='空奖'){ 
   $result['status']=1; 
   $result['name']=$res['yes']; 
  }else{ 
   $result['status']=-1; 
   $result['msg']=$res['yes']; 
  } 
  //return $result; 
  var_dump($result);
 } 

 //计算中奖概率
 function get_rand($proArr) { 
  $result = ''; 
  //概率数组的总概率精度 
  $proSum = array_sum($proArr); 
  // var_dump($proSum);
  //概率数组循环 
  foreach ($proArr as $key => $proCur) { 
  $randNum = mt_rand(1, $proSum); //返回随机整数 

  if ($randNum <= $proCur) { 
   $result = $key; 
   break; 
  } else { 
   $proSum -= $proCur; 
  } 
  } 
  unset ($proArr); 
  return $result; 
 }