对属于另一个数组的php数组进行排序


Sort an php array that is part of another array

我有一个类似的数组

"entry a" => [
    "type": 3,
    "id": 1,
    "content" => [
        [
            "name" => "somename a",
            "date": => "2011-08-2"
        ],
        [
            "name" => "somename b",
            "date": => "2012-04-20"
        ],
        [
            "name" => "somename c",
            "date": => "2015-01-14"
        ],
    ]
],
 "entry b" => [
    "type": 3,
    "id": 2,
    "content" => [
        [
            "name" => "someothername a",
            "date": => "2011-01-6"
        ],
        [
            "name" => "someothername b",
            "date": => "2015-12-24"
        ],
        [
            "name" => "someothername c",
            "date": => "2016-01-01"
        ],
    ]
],
...

我只想按日期对每个条目的"内容"数组进行排序。我尝试了以下内容;

        foreach ($cfArray as $cfEntry) {
            if($cfEntry['type'] == '3' && !is_null($cfEntry['content'])) {
                $content = $cfEntry['content'];
                uasort($content, function($a, $b) {
                    $a_end = strtotime($a['date']);
                    $b_end = strtotime($b['date']);
                    return ($a_end > $b_end) ? -1 : 1;
                });
                $cfEntry['content'] = $content;
            }
        }

如果我比较排序前后的$content,它已经更改,但我的$cfArray没有更改。为什么?有其他方法可以分类吗?

您的代码几乎可以工作了,您可以通过以下示例将更改的项目保存到$newCfArray数组来创建它:

$newCfArray = array();
foreach ($cfArray as $key => $cfEntry) {
    if($cfEntry['type'] == '3' && !is_null($cfEntry['content'])) {
        $content = $cfEntry['content'];
        uasort($content, function($a, $b) {
            $a_end = strtotime($a['date']);
            $b_end = strtotime($b['date']);
            return ($a_end > $b_end) ? -1 : 1;
        });
        $cfEntry['content'] = $content;
    }
    $newCfArray[$key] = $cfEntry;
}
$cfArray = $newCfArray;