PHP：Datetime :: Diff结果比较 [英] PHP: Datetime::Diff results comparison

问题描述

我正在尝试比较两个日期之间的差异，但是结果似乎是错误的，例如以下代码：

i was trying to compare the difference between 2 dates, but it seems the results are pretty wrong, for example this code:

$datetime1 = new DateTime('2009-10-11');
$datetime2 = new DateTime('2009-10-13');
$interval = $datetime1->diff($datetime2);
echo $interval->format('%R%a days')."<br />";

$datetime1 = new DateTime('2009-10-11');
$datetime2 = new DateTime('2009-10-15');
$interval2 = $datetime1->diff($datetime2);
echo $interval2->format('%R%a days')."<br />";

if($interval == $interval2){ echo "true"; }else{echo "false"; }

返回true，但在上面您可以看到日期差异并不相同，实际上是回显打印+2和+4。对如何比较2个日期差有任何想法吗？

Returns true, but above you can see the date differences are not the same, in fact echo prints +2 and +4. Any idea in how to compare 2 date differences?

编辑：datetime :: diff返回dateinterval对象，实际上它没有实现比较运算符， https://bugs.php.net/bug.php?id=49914
我将使用dateinterval vars检查差异，谢谢答案

the datetime::diff returns a dateinterval object, in fact it doesn't implement comparison operators, https://bugs.php.net/bug.php?id=49914 I'll use dateinterval vars to check the difference, thanks for the answers

推荐答案

似乎DateInterval在内部没有实现比较功能。扩展允许为其预定义的类定义自定义比较规则。显然，可以归结为一个松散的比较，即对象是同一类。

It seems that DateInterval doesn't implement a comparison function internally. Extensions are allowed to define custom comparison rules for their predefined classes. Evidently it falls back to a loose comparison that the objects are of the same class.

此功能请求提供了一个补丁，用于在其中添加此功能，但似乎在任何时候都未将其添加到源代码中。

This feature request provides a patch to add this functionality in, but it doesn't seem to have made it into the source at any point.

要解决此问题，您可以自己比较对象的每个成员变量（年，月等），也可以将每个对象强制转换为数组：

To get around this issue, you can either compare each member variable of your objects yourself (years, months etc.) or you can cast each object to an array:

if ((array) $interval == (array) $interval2) {
    echo 'true';
} else {
    echo 'false';
}

这篇关于PHP：Datetime :: Diff结果比较的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！