<?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(); } }
forexample
$awards = array( '0' => array('pro' => 15, 'info' => '15%的可能性'), '1' => array('pro' => 25, 'info' => '25%的可能性'), '2' => array('pro' => 40, 'info' => '40%的可能性'), '3' => array('pro' => 20, 'info' => '20%的可能性'), ); lottery_tool::setProField('pro'); lottery_tool::setAwards($awards); $result = array(); for ($i = 10000; $i --;) { $result[] = lottery_tool::roll(); } foreach ($result as $key => $value) { $awards[$value['roll_key']]['num'] ++; } echo '<pre class="brush:php;toolbar:false">'; var_dump($awards); //结果: 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