递归函数里面的类与foreach更改公共值，它不应该 [英] Recursive function inside class with foreach changes public value where it shouldn't
问题描述
好的，我真的很抱歉。我希望你能帮助我。
Ok, I'm really stucked with this. I hope you can help me.
我有我的类，用于管理分层数据。输入是一个具有以下结构的平面数组（只是一个例子）：
I have my class, used to manage hierarchical data. The input is a plain array with the following structure (just an example):
$list = array(
(object) array('id' => 1, 'nombre' => 'Cámaras de fotos', 'parentId' => null),
(object) array('id' => 2, 'nombre' => 'Lentes', 'parentId' => null),
(object) array('id' => 3, 'nombre' => 'Zoom', 'parentId' => 2),
(object) array('id' => 4, 'nombre' => 'SLR', 'parentId' => 1),
(object) array('id' => 5, 'nombre' => 'Primarios', 'parentId' => 2),
(object) array('id' => 6, 'nombre' => 'Sensor APS-C', 'parentId' => 4),
(object) array('id' => 7, 'nombre' => 'Full-frame', 'parentId' => 4),
(object) array('id' => 8, 'nombre' => 'Flashes', 'parentId' => null),
(object) array('id' => 9, 'nombre' => 'Compactas', 'parentId' => 1)
);
我以这种方式将数据输入类：
I input the data to the class this way:
$Hierarchical = new Hierarchical;
$Hierarchical->plain = $list;
然后我有一个公共函数（ createTree ）创建列表的多维数组表示。它工作完美。它可以返回结果或将它存储在 $ this-> tree 中。
Then I have a public function (createTree) to create a multidimensional array representation of the list. It works perfectly. It can return the result or store it inside $this->tree.
如您所见，这非常简单。它调用私有函数 iterateTree ，这是递归函数。
As you can see, this is very simple. It calls private function iterateTree, which is the recursive function.
class Hierarchical {
public $plain = array();
public $tree = array();
public function createTree($parentId=0, $return=false) {
$tree = $this->iterateTree($parentId);
if(!$return) {
$this->tree = $tree;
} else {
return $tree;
}
}
private function iterateTree($parentId) {
$resArray = array();
foreach($this->plain as $item) {
if($item->parentId == $parentId) {
$children = $this->iterateTree($item->id);
if( count($children) > 0 ) {
$item->children = $children;
}
$resArray[] = $item;
}
}
return $resArray;
}
}
好。它工作正常。
但是... 当我想使用 $ this-> plain 调用 createTree（）后。不是返回原始数据集，而是返回原始输入之间的某种混合，其中所有的子代都附加（类似于 $ this-> tree ）。
BUT... The problem appears when I want to use $this->plain after calling createTree(). Instead of returning the original dataset, it returns some kind of mix between the original input, with all their children appended (similar to $this->tree).
我不知道为什么 $ this-> plain 的内容正在更改，这两个函数使用我改变它的内容。
I can't figure out why the content of $this->plain is being changed, neither in the both functions used I'm changing it's content.
我已经尝试取消了 foreach 中的变量， foreach ，甚至将原始数组作为参数传递，而不是在递归函数中使用 $ this-> plain 。没有什么工作。
I've tried unseting the variables inside the foreach, after the foreach, even passing the original array as an argument and not using $this->plain at all inside the recursive function. Nothing worked.
我也不在类中使用任何可能改变它的值的其他函数。
I'm also not using any other function inside the class that could change it's value.
这是一个完全的mistery！
It's a total mistery!
推荐答案
$ c> foreach loop $ item 将引用数组中的对象，因此您要更改该行中的同一对象
In your foreach loop $item will be a reference to the object in the array, so you are changing that same object in the line
$item->children = $children;
这将影响原始数组中引用的对象 $ list 和 $ this-> plain 。
This will affect the object referred to in the original arrays $list and $this->plain.
一个解决方案可能是克隆 $ item 。
One solution may be to clone $item within your foreach loop.
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