PHP将类添加到另一个类[关闭]

Question

我想用start 开始订阅，如果addTrail 目前改变start 的结果。

无需试用期即可开始订阅

 (new Premium)->start(1, 'paid', 30);

开始订阅，试用期为 15 天

 (new Premium)->start(1, 'paid', 30)->addTrial(15);

说明

class Premium
{
    private $trialDays;

    public function start($user_id, $type, $endsInDays) {

        if($trialDays) {
            $endsInDays = $endsInDays + $trialDays;
        }

        return 'Your subscription will end in ' . $endsInDays . 'days';

    }

    public function addTrial($days) {
        $this->trialDays = $days;
    }

}

Answer 1

如果你想“链接”方法，你的启动函数必须return $this;

public function start($user_id, $type, $endsInDays) {
    if($trialDays) {
        $endsInDays = $endsInDays + $trialDays;
    }
    return $this;
}

否则使用标准语法

$premium = new Premium;
$premium->start(1,'paid',30);
$premium->addTrial(15);