oop tutorials

[Jarrett Billingsley]

"Saaa" <empty at needmail.com> wrote in message 
news:fqjknh$2lrm$1 at digitalmars.com...
> Thanks,
> Why isn't it initialized?
> I mean, when are these null referenced class pointers useful?

The same time any null pointer is useful - when you want to use it as a 
sentinel for some reason.

D is certainly not unique in this regard.  In all the languages I've ever 
used or seen, not one will automatically allocate an object when you declare 
a reference or pointer to one.

Maybe you're getting confused by C++ (I don't know your background) where:

Class c;
c.foo();

is legal, but something entirely different is happening here.  This is more 
like a D struct, where the class is allocated on the stack, not the heap. 
In D:

struct Struct
{
    void foo() {}
}

...
Struct s;
s.foo();

The D code:

Class c = new Class;
c.foo();

Translates to:

Class* c = new Class();
c->foo();

in C++.  Again, C++ will not automatically allocate a new class if you just 
write "Class* c".