php随机抽奖实例分析

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。    
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);