Question

我搜索了这个，似乎与此相似的那些都将成为＆＃34; custom＆＃34;基于海报的原始阵列结构。

我正在努力让下面的数组按每个条目的[DateTime]键排序。我希望它们按升序排序（具有最高数组索引的最新日期时间），并且如果可能的话，我希望保留数组结构和键。

Array
(
[0] => Array
    (
        [Source] => SimpleXMLElement Object
            (
                [0] => RTU-12 Merchandise Support, Fan Status Switch
            )

        [EventType] => SimpleXMLElement Object
            (
                [0] => Alarm Recall
            )

        [Description] => SimpleXMLElement Object
            (
                [0] => No Flow
            )

        [DateTime] => 07-25-2015 20:09:47
        [Priority] => SimpleXMLElement Object
            (
                [0] => Medium
            )

        [SubSystemKey] => SimpleXMLElement Object
            (
                [0] => 2
            )

        [ViewKey] => SimpleXMLElement Object
            (
                [0] => 7
            )

    )

[1] => Array
    (
        [Source] => SimpleXMLElement Object
            (
                [0] => RTU-03 Checkout Area, Fan Status Switch
            )

        [EventType] => SimpleXMLElement Object
            (
                [0] => Alarm Recall
            )

        [Description] => SimpleXMLElement Object
            (
                [0] => No Flow
            )

        [DateTime] => 07-25-2015 20:09:44
        [Priority] => SimpleXMLElement Object
            (
                [0] => Medium
            )

        [SubSystemKey] => SimpleXMLElement Object
            (
                [0] => 2
            )

        [ViewKey] => SimpleXMLElement Object
            (
                [0] => 7
            )

    )

......为了可读性而取消了一些指数......

[12] => Array
    (
        [Source] => SimpleXMLElement Object
            (
                [0] => ~RackA\SGr2\Cmp4, Proof of Running
            )

        [EventType] => SimpleXMLElement Object
            (
                [0] => Alarm Recall
            )

        [Description] => SimpleXMLElement Object
            (
                [0] => No Proof
            )

        [DateTime] => 07-25-2015 19:39:13
        [Priority] => SimpleXMLElement Object
            (
                [0] => Medium
            )

        [SubSystemKey] => SimpleXMLElement Object
            (
                [0] => 1
            )

        [ViewKey] => SimpleXMLElement Object
            (
                [0] => 2
            )

    )

[13] => Array
    (
        [Source] => SimpleXMLElement Object
            (
                [0] => ~RackC\SGr1, Suction Pressure
            )

        [EventType] => SimpleXMLElement Object
            (
                [0] => Alarm
            )

        [Description] => SimpleXMLElement Object
            (
                [0] => Pressure too high
            )

        [DateTime] => 07-25-2015 19:14:21
        [Priority] => SimpleXMLElement Object
            (
                [0] => Medium
            )

        [SubSystemKey] => SimpleXMLElement Object
            (
                [0] => 1
            )

        [ViewKey] => SimpleXMLElement Object
            (
                [0] => 4
            )

    )

[Count] => 14
[NewEvents] => 14
[Result] => Success
)

以下是我迄今为止所做的尝试：

function date_compare($a, $b)
{
    $t1 = strtotime($a['DateTime']);
    $t2 = strtotime($b['DateTime']);
    return $t1 > $t2;
}    

usort($alarms, 'date_compare');

我的结果只是一个未排序（看似破碎的组织）数组。我对usort不太熟练，所以寻找一些指导。

谢谢！

Answer 1

似乎strtotime()无法解析此日期格式：07-25-2015 19:39:13，这已通过一些快速实验得到证实：

var_dump(strtotime("07-25-2015 19:39:13"));

布尔（假）

var_dump(strtotime("07/25/2015 19:39:13"));

INT（1437845953）

此处提供strtotime()可使用的日期格式的详细列表：
http://php.net/manual/en/datetime.formats.date.php

解决此问题的最快方法是将破折号转换为斜杠：

function date_compare($a, $b) {
    $t1 = strtotime(str_replace('-', '/', $a['DateTime']));
    $t2 = strtotime(str_replace('-', '/', $b['DateTime']));
    return $t1 > $t2;
}

usort($alarms, 'date_compare');

您可能希望使用uasort()来保留数组的键 http://php.net/manual/en/function.uasort.php

还要考虑这个：

如果第一个参数被认为分别小于，等于或大于第二个参数，则比较函数必须返回小于，等于或大于零的整数。

http://php.net/manual/en/function.usort.php

因此：

function date_compare($a, $b) {
    $t1 = strtotime(str_replace('-', '/', $a['DateTime']));
    $t2 = strtotime(str_replace('-', '/', $b['DateTime']));
    return $t1 > $t2 ? -1 : 1;
}

uasort($alarms, 'date_compare');

Answer 2

你也可以使用带有“NATURAL”标志的array_multisort。

$dateTime = array();
foreach ($array as $tempArray) {         
    $dateTime[] = $tempArray["DateTime"];    
 }

 array_multisort($dateTime, SORT_NATURAL, $array);

得到了一些帮助 http://shiflett.org/blog/2011/jun/sorting-multi-dimensional-arrays-in-php

PHP自定义排序多维数组按日期时间字段

2 个答案: