Question

我正在尝试对一个多维数组进行排序（实际上它是多维的并不重要，因为我总是只排序一个维度。）

function orderSort($a, $b) {
    if ($a['order'] == $b['order']) return 0;

    return($a['order'] < $b['order']) ? -1 : 1;
}

$nav = array(
    "section" => array(
        "header" => array(),
        "main" => array()
    ),
    "link" => array(
        "header" => array(),
        "main" => array()
    )
);

$DATA = array(
    array(
        "type" => "section",
        "subtype" => "main",
        "data" => array("name" => "/Basic", "order" => 1, "parent" => "bbb")
    ),
    array(
        "type" => "link",
        "subtype" => "main",
        "data" => array("name" => "Home", "link" => array("/"), "order" => 1, "parent" => "/Basic")
    )
);

foreach($DATA as $ele) {
    if(!array_key_exists($ele['data']['parent'], $nav[$ele['type']][$ele['subtype']]))
        $nav[$ele['type']][$ele['subtype']][$ele['data']['parent']] = array($ele['data']);
    else
        array_push($nav[$ele['type']][$ele['subtype']][$ele['data']['parent']], $ele['data']);
    }

var_dump($nav['section']['main']);
echo '<br><br>';

foreach($nav['section']['main'] as $ele) {
    uasort($ele, 'orderSort');
    $nav['section']['main'] = $ele;
}

var_dump($nav['section']['main']);

第一个var_dump返回：

array(1) { 
    ["bbb"]=> array(1) { 
        [0]=> array(3) { 
            ["name"]=> string(6) "/Basic" 
            ["order"]=> int(1) ["parent"]=> string(3) "bbb" 
        } 
    } 
}

正如您所看到的，有一个名为bbb的密钥（对不起......高度概念化）。现在第二个输出：

array(1) { 
    [0]=> array(3) { 
        ["name"]=> string(6) "/Basic" 
        ["order"]=> int(1) 
        ["parent"]=> string(3) "bbb" 
    } 
}

突然bbb消失了。实际上整个数组（只有一个元素）已经消失了。

我的问题是，我可以以某种方式阻止这种情况发生吗？我从来没有要求过这种优化。当然只用一个元素对它进行排序没有任何意义，但仍然存在。

Answer 1

foreach($nav['section']['main'] as $ele) {
    uasort($ele, 'orderSort');
    $nav['section']['main'] = $ele;
}

好。哪个是关键？你忘记了键（你用新数组而不是原始数组本身覆盖原始数组的父级）：

foreach($nav['section']['main'] as $key => $ele) {
    uasort($ele, 'orderSort');
    $nav['section']['main'][$key] = $ele;
}

是正确的，但参考更好：

foreach($nav['section']['main'] as &$ele) {
    uasort($ele, 'orderSort');
}

Answer 2

你的问题在这里：

foreach($nav['section']['main'] as $ele) {
    uasort($ele, 'orderSort');
    $nav['section']['main'] = $ele;
}

这需要

foreach($nav['section']['main'] as $index => $ele) {
    uasort($ele, 'orderSort');
    $nav['section']['main'][$index] = $ele;
}

你用第一个元素替换了整个$ nav ['section'] ['main']。

uasort正在删除键/数组

2 个答案: