PHP - 将匿名函数分配给自己函数内部的变量并使用它[关闭]

Question

So I'm trying to do something like this:

function func() {

    $call = function() {
        ...
    };

    $call();

}

But it's throwing an error saying:

Function name must be a string

I also tried calling the function like this:

$this->call();
call(); // and like this

And it's not working as well.

Is there a reason why I can't do what I'm doing?

EDIT

It seems to be a problem with the original code, and not in the example I wrote

This is my real code:

$data = [...];
$menu_array = [];
$getChildren = function($id) {
          $children = [];
          foreach ($data as $node) {
              if ($id == $node["parent"]) {
                  array_push($children, $node);
              }
          } 
          return empty($children) ? null : $children;
        };

        $check = function($arr, $dat) {
            foreach ($dat as $node) {
                $children = $getChildren($node["id"]);
                if ($children == null) {
                    $arr[$node["display_name"]] = $node["model"];
                } else {
                    $arr[$node["display_name"]][] = $children;
                    $check($children);
                }
            }
        };
$check($menu_array, $data);

The error is thrown in this line:

$children = $getChildren($node["id"]);

Answer 1

What you want to do here, is recursion! The problem is, that PHP does not automatically add any variables from the outer scope, into the function scope. In your code $check($children);, the variable $check is actually not defined.

You can fix this by telling PHP that it should use the $getChildren and $check variable from outside the function:

$getChildren = function($id) use (&$getChildren) {
   ...

and

$check = function($arr, $dat) use (&$check, &$getChildren) {
  ...

Adapted from https://stackoverflow.com/a/2480242/2681964