PHP Infinite Class Classification code problem

I tried to write an infinite class classification, the results of some problems, think for a long time, feel the code is OK, but the result is not correct. Now the whole person is ignorant ....

The chestnut on the net read some, seemingly the wording is different from mine.

The array structure is as follows:

Array ([0] = = Array ([id] = 1 [name] + + code [Parent] = 0) [1] = = Array ([id] = 3 [name] + = anime [parent] + 0) [2 ] = = Array ([id] = 4 [Name] = Heal [Parent] + 3) [3] =&gt ;        Array ([id] = 5 [name] + motivational [parent] + 3) [4] = = Array        ([id] = 6 [name] = = [Parent] + 3) [5] = = Array            ([id] = 7 [Name] = Lily [Parent] = 3) [6] = = Array (            [id] = 8 [Name] = resource [parent] + 0) [7] = = Array ( [id] = 9 [name] + + app [parent] + 8) [8] = = = Array ([ID            ] = 10[Name] + software [parent] + 8) [9] = = Array ([id] = = [Name] ] = Black technology [parent] + 8))

Where id is the category unique ID, which parent is the parent class ID
I wrote the following code:

    function all($id=0){            static $_class = null;            if(is_null($_class))                    $_class = select();  //这个得出来的就是以上的数组结构，然后赋值给了`$_class`变量            $result = array();            foreach($_class as $k => $v){                    if($v['parent'] == $id){                            unset($_class[$k]);                            $v = array_merge($v, $this->all($v['id']));                            $result['child'][] = $v;                    }            }            return $result;    }    print_r(all(0));

Reply content:

I tried to write an infinite class classification, the results of some problems, think for a long time, feel the code is OK, but the result is not correct. Now the whole person is ignorant ....

The chestnut on the net read some, seemingly the wording is different from mine.

The array structure is as follows:

Array ([0] = = Array ([id] = 1 [name] + + code [Parent] = 0) [1] = = Array ([id] = 3 [name] + = anime [parent] + 0) [2 ] = = Array ([id] = 4 [Name] = Heal [Parent] + 3) [3] =&gt ;        Array ([id] = 5 [name] + motivational [parent] + 3) [4] = = Array        ([id] = 6 [name] = = [Parent] + 3) [5] = = Array            ([id] = 7 [Name] = Lily [Parent] = 3) [6] = = Array (            [id] = 8 [Name] = resource [parent] + 0) [7] = = Array ( [id] = 9 [name] + + app [parent] + 8) [8] = = = Array ([ID            ] = 10[Name] + software [parent] + 8) [9] = = Array ([id] = = [Name] ] = Black technology [parent] + 8))

Where id is the category unique ID, which parent is the parent class ID
I wrote the following code:

    function all($id=0){            static $_class = null;            if(is_null($_class))                    $_class = select();  //这个得出来的就是以上的数组结构，然后赋值给了`$_class`变量            $result = array();            foreach($_class as $k => $v){                    if($v['parent'] == $id){                            unset($_class[$k]);                            $v = array_merge($v, $this->all($v['id']));                            $result['child'][] = $v;                    }            }            return $result;    }    print_r(all(0));

Unset ($_class[$k]);
This line removes

In view of the fact that you are still using the recursive return, I am here to provide 2 methods, one is recursive, and the other is pointer shape.

The second may not be understandable to you for the time being, but to help you learn and to be convenient to others, here is the code:

Use recursion

// 呃，我真不忍心写出这个循环那么多遍的代码，求神解救我。function _data_to_tree(&$items, $topid = 0, $with_id = TRUE){    $result = [];    foreach($items as $v)        if ($topid == $v['parent'])  {            $r = $v + ['children' => _data_to_tree($items, $v['id'], $with_id)];            if ($with_id)                $result[$v['id']] = $r;            else                $result[] = $r;        }                return $result;}

Using PHP's pointer properties

function _data_to_tree($items, $topid = 0, $with_id = TRUE){    if ($with_id)        foreach ($items as $item)            $items[ $item['parent'] ]['children'][ $item['id'] ] = &$items[ $item['id'] ];    else        foreach ($items as $item)                $items[ $item['parent'] ]['children'][] = &$items[ $item['id'] ];         return isset($items[ $topid ]['children']) ? $items[ $topid ][ 'children' ] : [];}

Use

Pass in your above array, for example, the top-most ID is 0

$data = [   ['id' => 4, 'parent' => 1 , 'text' => 'Parent1'],    ['id' => 1, 'parent' => 0 , 'text' => 'Root'],   ['id' => 2, 'parent' => 1 , 'text' => 'Parent2'],    ['id' => 3, 'parent' => 2 , 'text' => 'Sub1'], ];print_r ( _data_to_tree($data, 0) );

Results

Array ([1] = = Array ([id] = 1 [Parent] = 0 [Text] = Root                            [Children] = = Array ([4] = = Array (                            [id] = 4 [Parent] + 1 [text] = Parent1                        [children] = = Array ()                            ) [2] = = Array ([id] = 2 [Parent] = 1 [Text] = Parent2 [children] =& Gt                                        Array ([3] = = Array  ([id] = 3 [Parent] = =                  2                          [Text] = Sub1 [children] = = Array                                        (                                                ) )                                )                        )                )        ))

