php无限极分类的方法是什么

PHP无限极分类的方法有多种，下面是其中一种常见的方法：

使用递归函数：首先，构建一个多维数组来表示分类的层级关系。每个分类包含一个id和parent_id，parent_id表示该分类的父级分类id。然后，编写一个递归函数来遍历该多维数组，根据parent_id将子分类添加到对应的父分类下。可以使用一个空数组来存储最终的无限极分类结果。

以下是一个示例代码：

function buildTree($categories, $parent_id = 0) {    $tree = array();        foreach ($categories as $category) {        if ($category['parent_id'] == $parent_id) {            $children = buildTree($categories, $category['id']);            if (!empty($children)) {                $category['children'] = $children;            }            $tree[] = $category;        }    }        return $tree;}

使用示例：

$categories = array(    array('id' => 1, 'name' => '分类1', 'parent_id' => 0),    array('id' => 2, 'name' => '分类2', 'parent_id' => 0),    array('id' => 3, 'name' => '分类3', 'parent_id' => 1),    array('id' => 4, 'name' => '分类4', 'parent_id' => 1),    array('id' => 5, 'name' => '分类5', 'parent_id' => 2),    array('id' => 6, 'name' => '分类6', 'parent_id' => 3),    array('id' => 7, 'name' => '分类7', 'parent_id' => 3),);$tree = buildTree($categories);print_r($tree);

输出结果：

Array(    [0] => Array        (            [id] => 1            [name] => 分类1            [parent_id] => 0            [children] => Array                (                    [0] => Array                        (                            [id] => 3                            [name] => 分类3                            [parent_id] => 1                            [children] => Array                                (                                    [0] => Array                                        (                                            [id] => 6                                            [name] => 分类6                                            [parent_id] => 3                                        )                                    [1] => Array                                        (                                            [id] => 7                                            [name] => 分类7                                            [parent_id] => 3                                        )                                )                        )                    [1] => Array                        (                            [id] => 4                            [name] => 分类4                            [parent_id] => 1                        )                )        )    [1] => Array        (            [id] => 2            [name] => 分类2            [parent_id] => 0            [children] => Array                (                    [0] => Array                        (                            [id] => 5                            [name] => 分类5                            [parent_id] => 2                        )                )        ))

这样就可以将多维数组按照层级关系转换成无限极分类。