Design Patterns-an example of a PHP combination pattern related issues

  _name = $name; } function Remove (MenuComponent $component) {} function Add (MenuComponent $component) {$this->_item    s[$component->getname ()] = $component;    } function GetName () {return $this->_name;              } public Function displayoperation () {Static $align = ' | ';                  $align. = '; echo $this->_name, "
";              foreach ($this->_items as $name = + $item) {echo $align;          $item->displayoperation ();        }}}class client{static function DisplayMenu () {$subMenu 1 = new Menucomposite (' submenu1 ');        $subMenu 1->add ($subMenu 1);    $subMenu 1->displayoperation (); }}client::d isplaymenu ();

The output is an infinite loop
Submenu1
|submenu1
|submenu1
...

Why is this, the first recursive call Displayoperation () after the foreach inside should be empty, stopped, why the infinite loop?

Reply content:

  _name = $name; } function Remove (MenuComponent $component) {} function Add (MenuComponent $component) {$this->_item    s[$component->getname ()] = $component;    } function GetName () {return $this->_name;              } public Function displayoperation () {Static $align = ' | ';                  $align. = '; echo $this->_name, "
";              foreach ($this->_items as $name = + $item) {echo $align;          $item->displayoperation ();        }}}class client{static function DisplayMenu () {$subMenu 1 = new Menucomposite (' submenu1 ');        $subMenu 1->add ($subMenu 1);    $subMenu 1->displayoperation (); }}client::d isplaymenu ();

The output is an infinite loop
Submenu1
|submenu1
|submenu1
...

Why is this, the first recursive call Displayoperation () after the foreach inside should be empty, stopped, why the infinite loop?

The implementation of add$this->_items[$component->getName()] = $component;

Note $subMenu1->add($subMenu1);

实例$subMenu1的属性$_items["submenu1"]是他自己本身$subMenu1

And then infinity goes on ...

Class attribute $this->item has been the object you've instantiated, so this displayoperation () method has been circulating.

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