Php 按键值对数组排序

我有以下数组

Array ( [0] => Array ( [lastUpload] => [lastPost] => Sun Nov 23 2014 16:54:13 [username] => blt152561 [email] => user1@mail.com [joined] => Sun Nov 23 2014 16:49:09 [prodCount] => 2 [mediaCount] => 0 [userId] => 77292aaf-e540-465c-9319-8dd74c8d7f12 ) [1] => Array ( [lastUpload] => [lastPost] => [username] => mvbg40 [email] => user2@mail.com [joined] => Sun Nov 23 2014 9:31:43 [prodCount] => 0 [mediaCount] => 0 [userId] => a2998c68-1c9a-49b9-8c78-ced3cffaa109 ) [2] => Array ( [lastUpload] => Sun Nov 23 2014 7:54:03 [lastPost] => Sun Nov 23 2014 7:53:53 [username] => flexingladies [email] => user5@mail.com [joined] => Sun Nov 23 2014 7:47:44 [prodCount] => 1 [mediaCount] => 1 [userId] => 3b4b6aad-de95-428c-95ed-cb4fe963f322 ) [3] => Array ( [lastUpload] => [lastPost] => Sat Nov 22 2014 8:05:30 [username] => dewey [email] => user3@mail.com [joined] => Sat Nov 22 2014 8:02:01 [prodCount] => 1 [mediaCount] => 0 [userId] => 08220286-6a24-49ff-929b-ccb4e0e10c3e ) [4] => Array ( [lastUpload] => [lastPost] => Thu Nov 20 2014 18:43:56 [username] => mhirsen99 [email] => user4@mail.com [joined] => Thu Nov 20 2014 18:43:09 [prodCount] => 1 [mediaCount] => 0 [userId] => ddea4f04-b035-4e8d-a777-cb4a2813b705 ) )

我想按lastPost中的值对其进行排序

我不知道该怎么做。有人能给我指出正确的方向吗？我尝试了ksort，但它只是返回1，而不是已排序的数组。

尝试使用此命令

asort($array);

根据值按升序对数组排序

或

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要按降序对数组进行排序，可以根据值使用usort按键进行自定义排序

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usort（$array，function（$a，$b）{return$a['lastPost']-$b['lastPost']；}）
您必须使用foreach来实现此功能：

foreach ($array as $key => $value)
  $ordered[$value['lastPost']] = $value;

ksort($ordered, SORT_ASC);

只需在StackOverflow上搜索，或在这类搜索上搜索，但由于某种原因，那些没有['lastPost']键的搜索结果分散在结果中，根据排序号，它们应该都位于底部/顶部？您可以利用！empty（）、isset（）或array_key_exists（）不允许它们包含在排序数组中
foreach ($array as $key => $value)
  $ordered[$value['lastPost']] = $value;

ksort($ordered, SORT_ASC);