我需要根据>在数组键中出现的次数将单个数组分为子数组，这样我就可以判断谁是父类别，谁不是。请注意，可能嵌套的父对象的数量没有限制。
此外，如果存在具有相同名称的子项，则如果该子项具有不同的父项，则该子项将被视为唯一的。
我的源数组结构如下：
array (
'Test Parent 2>Test Child>Test Sub Child' =>
array (
'content_id_4' => NULL,
),
'Test Parent 3' =>
array (
'content_id_4' => NULL,
'content_id_5' => NULL,
),
'Test Parent>Test Child>Test Sub Child' =>
array (
'content_id_3' => NULL,
),
'Test Parent 2 with No Kids' =>
array (
'content_id_3' => NULL,
),
'Collections>Sports' =>
array (
'content_id_2' => NULL,
'content_id_22' => NULL,
),
'Collections' =>
array (
'content_id_2' => NULL,
'content_id_22' => NULL,
'content_id_6' => NULL,
),
'Collections>Charity' =>
array (
'content_id_6' => NULL,
),
)
在上面的示例中，Test Parent>Test Child>Test Sub Child意味着存在具有子类别Test Child的父类别Test Parent。Test Child也是一个父级，并且有一个名为Test Sub Child的子级，该子级没有任何子级。
所需输出示例：
array (
'Collections' =>
array (
'Sports' => NULL,
'Charity' => NULL,
),
'Test Parent' =>
array (
'Test Child' =>
array (
'Test Sub Child' => NULL,
),
),
'Test Parent 2 with No kids' => NULL,
'Study' =>
array (
'Study Groups' => NULL,
),
)
我尝试了一个解决方案，但无法获得正确的语法，这样我就可以用孩子的孩子创建一个额外的数组。
我不一定要求重构我的示例。我只是在寻找最有效的解决方案。
我的示例代码
$category_structure = array();
foreach($event_categories as $main_cat => $content_ids) {
$this_category_list = explode('>', $main_cat);
$this_cat = array();
$this_parent = array_shift($this_category_list);
foreach($this_category_list as $cat) {
$this_cat[$this_parent][$cat] = null;
}
$category_structure = array_merge_recursive($this_cat, $category_structure);
}
这应该对您有效，确保结果中没有零索引项。我认为它来自array_merge_recursive，通过将空值项与具有关联键的项合并。
不过，它不如P0rnflake的解决方案那么优雅，但我相信你会明白的。
$collect = array();
$result = array();
$last = "";
foreach($event_categories as $main_cat => $content_ids) {
if (strpos($last, $main_cat) === false) {
array_push($collect, explode('>', $main_cat));
}
$last = $main_cat;
}
array_walk($collect, function($value) use (&$result) {
$out = array();
$cur = &$out;
foreach ($value as $array) {
if (count($value) !== 1) {
$cur[$array] = array();
} else {
$cur[$array] = null;
}
$cur = &$cur[$array];
}
$cur = null;
$result = array_merge_recursive($result, $out);
});
var_dump($result);
此解决方案应适用于php>=5.3.0($yourArray是输入数组(：
// anonymous recursive function which merges a flat numeric array
// into a hierarchy, f.e. array('parent','child','grandchild')
// will be built to a hierarchical array
$treeBuilder = function($numArray) use (&$treeBuilder) {
if(isset($numArray[1])) {
//recursive merge needed, there are still entries left
return array(
$numArray[0] => $treeBuilder(array_slice($numArray, 1))
);
}
//end is reached
return array(
$numArray[0] => null
);
};
$result = array();
foreach (array_keys($yourArray) as $key) {
// loop through exploded keys and merge results
$hierarchy = explode('>', $key);
$result = array_merge_recursive($result, $treeBuilder($hierarchy));
}
var_dump($result);