[source lang="cpp"]
class Menu
{
private:
Menu * subMenu;
.....
};[/source]

is this possible?

[source lang="cpp"]
class Menu
{
private:
Menu * subMenu;
.....
};[/source]

is this possible?

Did you try to compile this? Simple question like this could just be tested. Learn to be more independent.

I of course tried this, but I asked this because I didn't know what to put in the constructor
[source lang="cpp"]Menu::Menu()
{
subMenu=new Menu()//??
}
[/source]

thanks, I see

We don't know what you need to do in your constructor either. But I can tell you one thing: you cannot allocate a new menu unconditionally in each menu, because each menu will contain a menu, which will contain a menu, which will contain a menu, which will contain a menu, which will... ad infinitum. Whatever you do, you must have some logic that controls when the chain breaks; that is, which menus don't contain a submenu.

This is a form of endless loop. Any loop that does not have a 100% valid, viable and usable exit condition is very bad.

This is a form of endless loop. Any loop that does not have a 100% valid, viable and usable exit condition is very bad.

Technically this would be recursion, and you would overflow the stack long before you run out of memory allocating [font=courier new,courier,monospace]Menu[/font] objects, unless [font=courier new,courier,monospace]Menu[/font] allocates hundreds of megabytes of data in addition to each child [font=courier new,courier,monospace]Menu[/font].

I of course tried this, but I asked this because I didn't know what to put in the constructor
[source lang="cpp"]Menu::Menu()
{
subMenu=new Menu()//??
}
[/source]

If you define an object type which invokes its own constructor within its constructor (like you've done above) it creates an infinite recursion, which is similar to an endless loop. Example ::

[source lang="cpp"]
class MyClass
{
public:
MyClass() {
myClass = new MyClass();
}

MyClass *myClass;
};

void main() {

MyClass* mc = new MyClass;
}
[/source]

As soon as the "main" function of this program starts it creates a new MyClass instance and invokes its constructor with the new operator... and then what happens? Control jumps to the MyClass constructor, MyClass::MyClass()... but the code in the constructor AGAIN invokes the constructor with the new operator, in an attempt to instantiate the myClass instance... but that myClass instance will have its own myClass instance too lol... So the constructor is invoked again, and again and again and never stops... at least not until you terminate the program! ;-)

A better way to handle this dilemma is allow the constructor in your program to take a Menu* parameter for its sub-menu... let outside code create the sub-menu (if the menu has one) and pass it to the new, primary menu instance. Alternatively you could offer a static (or even an instance) method in the Menu class, like [static] Menu::AddSubMenu(Menu* primary, <creation params> ) or [instance] Menu::AddSubMenu(...) and let that method handle adding the sub-menu to the primary menu...