按日期字段对对象数组进行排序

How can I re-arrange a array of objects like this:

如何重新排列这样的对象数组：

 [495] => stdClass Object
        (
         [date] => 2009-10-31 18:24:09
         ...
        )
 [582] => stdClass Object
        (
         [date] => 2010-2-11 12:01:42
         ...
        )
 ...

by the date key, oldest first ?

按日期键，最早的第一个？

4 个解决方案

#1

usort($array, function($a, $b) {
    return strtotime($a['date']) - strtotime($b['date']);
});

Or if you don't have PHP 5.3:

或者如果你没有PHP 5.3：

function cb($a, $b) {
    return strtotime($a['date']) - strtotime($b['date']);
}
usort($array, 'cb');

#2

Since the original question is about sorting arrays of stdClass() objects, here's the code which would work if $a and $b are objects:

由于最初的问题是关于对stdClass（）对象的数组进行排序，所以如果$ a和$ b是对象，这里的代码将起作用：

usort($array, function($a, $b) {
    return strtotime($a->date) - strtotime($b->date);
});

Or if you don't have PHP 5.3:

或者如果你没有PHP 5.3：

function cb($a, $b) {
    return strtotime($a->date) - strtotime($b->date);
}
usort($array, 'cb');

#3

I wanted to expand on arnaud576875's answer. I ran across this same issue, but with using DateTime objects. This is how I was able to accomplish the same thing.

我想扩展arnaud576875的答案。我遇到了同样的问题，但是使用了DateTime对象。这就是我能够完成同样的事情。

usort($array, function($a, $b) {
    return $a['date']->format('U') - $b['date']->format('U');
});

#4

I wanted to expand on arnaud576875 and Michael Irigoyen.

我想扩展arnaud576875和Michael Irigoyen。

Same issue with object containing dateTime with Symphony.

与包含Symphony的dateTime的对象相同的问题。

I coudn't use $a['date'] because it was not an key array.

我不能使用$ a ['date']，因为它不是一个关键数组。

usort($verifications, function($a, $b) {
   return $a->getDate()->format('U') - $b->getDate()->format('U');
});

This solved my problem

这解决了我的问题