PHP DateTime createFromFormat不会死于自然死亡

Question

我对createFromFormat的行为感到困惑.

    private function _event_date($eventdate) {

    $this->_logger->err($eventdate);

    $dt = new DateTime();

    $dt->createFromFormat(DATE_ISO8601, $eventdate);

    $formatted = $dt->format("m/d/Y");

    $this->_logger->err($formatted);

    return $formatted;
}

我多次调用_event_date.我希望当我创建一个新的DateTime对象时,它将接受$ eventdate并导致新的格式化日期.

奇怪的是(对我来说),我的输出看起来像这样:

2013-04-04 15:10:26 UTC error _event_date 2013-04-05T21:00:00-0400
2013-04-04 15:10:26 UTC error _event_date 04/04/2013
2013-04-04 15:10:26 UTC error _event_date 2013-04-12T20:00:00-0400
2013-04-04 15:10:26 UTC error _event_date 04/04/2013
2013-04-04 15:10:26 UTC error _event_date 2013-04-16T18:00:00-0400
2013-04-04 15:10:26 UTC error _event_date 04/04/2013
2013-04-04 15:10:26 UTC error _event_date 2013-04-17T19:30:00-0400
2013-04-04 15:10:26 UTC error _event_date 04/04/2013
2013-04-04 15:10:26 UTC error _event_date 2013-04-18T20:00:00-0400
2013-04-04 15:10:26 UTC error _event_date 04/04/2013

看来由于某种原因,DateTime持有我原来的$ eventdate值.

为什么是这样？我是否误解了createFromFormat的工作原理？我错过了PHP的对象模型吗？PHP在我的饮料中加了些东西吗？

--------------回答----------------

Marc B的答案确实解决了这个问题:

    // month/day/year
private function _event_date($eventdate) {

    $this->_logger->err($eventdate);

    $dt = DateTime::createFromFormat(DATE_ISO8601, $eventdate);

    $formatted = $dt->format("m/d/Y");

    $this->_logger->err($formatted);

    return $formatted;
}

这产生了正确的结果:

2013-04-04 15:34:56 UTC error _event_date 2013-04-04T19:30:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/04/2013
2013-04-04 15:34:56 UTC error _event_date 2013-04-05T21:00:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/05/2013
2013-04-04 15:34:56 UTC error _event_date 2013-04-12T20:00:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/12/2013
2013-04-04 15:34:56 UTC error _event_date 2013-04-16T18:00:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/16/2013
2013-04-04 15:34:56 UTC error _event_date 2013-04-17T19:30:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/17/2013
2013-04-04 15:34:56 UTC error _event_date 2013-04-18T20:00:00-0400
2013-04-04 15:34:56 UTC error _event_date 04/18/2013

Answer 1

createFromFormat是一个静态方法,Try

$date = DateTime::createFromFormat(DATE_ISO8601, $eventdate);

代替.

它返回一个你没有捕获的DateTime对象,所以是的,你正在"记住"之前设置的日期,恰好是"现在",因为你没有将日期作为构造函数参数传递.