本文实例讲述了php随机抽奖用法。分享给大家供大家参考。具体分析如下：

1. 按照设定的概率，得到随机抽奖的结果。
复制代码 代码如下:<?php
/**
* 抽奖工具
*/
class lottery_tool {
protected static $awardsArr;
protected static $proField = 'probability';
protected static $proSum = 0;
protected static $checkAward = false;
const SUCCESS_CODE = 0;
const FAIL_CODE = -1;
//检查抽奖数据
protected static function checkAwards(){
if (!is_array(self::$awardsArr) || empty(self::$awardsArr)) {
return self::$checkAward = false;
}
self::$proSum = 0;
foreach (self::$awardsArr as $_key => $award) {
self::$proSum += $award[self::$proField];
}
if (empty(self::$proSum)) {
return self::$checkAward = false;
}
return self::$checkAward = true;
}
protected static function successRoll($rollKey){
return array('code' => self::SUCCESS_CODE, 'roll_key' => $rollKey, 'msg' => 'roll success');
}
protected static function failRoll($msg = 'roll fail'){
return array('code' => self::FAIL_CODE, 'msg' => $msg );
}
//抽奖
public static function roll () {
if (false == self::$checkAward) {
return self::failRoll('awards data is not the right format!');
}
$result = mt_rand(0, self::$proSum);
$proValue = 0;
foreach (self::$awardsArr as $_key => $value) {
$proValue += $value[self::$proField];
if ($result <= $proValue) {
return self::successRoll($_key);
}
}
return self::failRoll('wrong');
}
//改变概率字段名
public static function setProField($field = null) {
if (!empty($field)) {
self::$proField = $field;
}
}
//设置奖品
public static function setAwards($awards){
self::$awardsArr = $awards;
self::checkAwards();
}
}
2. 示例代码：
复制代码 代码如下:$awards = array(
'0' => array('pro' => 15, 'info' => '15%的可能性'),
'1' => array('pro' => 25, 'info' => '25%的可能性'),
'2' => array('pro' => 40, 'info' => '40%的可能性'),
'3' => array('pro' => 20, 'info' => '20%的可能性'),
);
lottery_tool::setProField('pro');
lottery_tool::setAwards($awards);
$result = array();
for ($i = 10000; $i --;) {
$result[] = lottery_tool::roll();
}
foreach ($result as $key => $value) {
$awards[$value['roll_key']]['num'] ++;
}
echo '<pre>';
var_dump($awards);

运行结果如下：
复制代码 代码如下:array
0 =>
array
'pro' => int 15
'info' => string '15%的可能性' (length=15)
'num' => int 1596
1 =>
array
'pro' => int 25
'info' => string '25%的可能性' (length=15)
'num' => int 2484
2 =>
array
'pro' => int 40
'info' => string '40%的可能性' (length=15)
'num' => int 3939
3 =>
array
'pro' => int 20
'info' => string '20%的可能性' (length=15)
'num' => int 1981

希望本文所述对大家的php程序设计有所帮助。