php 订单号 随机数

0x01 订单号

	function getdingdan()
	{
		$str = '0123456789';
		$time = date('YmdHis');
		for ($i = 0; $i < 3; $i++) {
			$time .= $str[mt_rand(0, 9)];
		}
        return $time;
	}

0x02 随机数

    public function getRandStr($length = 5)
    {
        //字符组合
        $str = 'abcdefghigklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $len = strlen($str) - 1;
        $randstr = '';
        for ($i = 0; $i < $length; $i++) {
            $num = mt_rand(0, $len);
            $randstr .= $str[$num];
        }
            return $randstr;
    }