php 实现抽奖功能

抽奖功能 1

最近做的小程序有一个抽奖功能，这里记录下实现抽奖功能的具体流程

前提：

有一组奖品数据如下

id奖品(prize)概率(rate)数量(num)已抽数量(prize_num)1一等奖10%1002二等奖15%2003三等奖35%500

根据如上实现抽奖如下($prizes表示上面表格数据)

public function promise()
	{
		$prizes = [
			[
				'id' => 1,
				'prize' => '一等奖',
				'rate' => '0.1',
				'num' => '10',
				'prize_num' => '0',
			],
			[
				'id' => 2,
				'prize' => '二等奖',
				'rate' => '0.15',
				'num' => '20',
				'prize_num' => '0',
			],
			[
				'id' => 3,
				'prize' => '三等奖',
				'rate' => '0.3',
				'num' => '50',
				'prize_num' => '0',
			],
		];
		//进行抽奖
		$data = [];
		foreach ($prizes as $prize) {
		    if (($prize['num'] - $prize['prize_num']) > 0) {
		        $data[$prize['id']] = 100 * ($prize['rate']);
		    }
		};
		//获取所有奖品的总概率
		$sum = array_sum($data);
		$countSum = 100;
		if ($sum  $value) {
		    $randNum = mt_rand(1, $countSum);
		    if ($randNum