Re: How To Check if an object is created (instantiated)?

mohamad@[EMAIL PROTECTED]
 wrote:

> I have this simple code that I could find an answer to yet without
> trigiring an exceptiom.
> 
> 
> Type
>   TMyClass = Class (tobject);
>      Item : integer;
>   end;
> 
> 
> procedure Somename(Var R : TMyClass);
> begin
> ...
>   Now, inside a program how can I check to see if the Variable R has
> an instance?

You can't. If R is not initialized, and a local variable, it can have
any value, and there is no viable way to find out if that value is a
random value pointing to a random spot in memory or a valid value that
points to a valid instance.

Now, if your code is designed properly, you'll never have to ask this
question. If you are just the author of the procedure, and have no idea
who will call your procedure, the responsibility is on the user to make
sure that a valid instance is passed.

-- 
Rudy Velthuis        http://rvelthuis.de

"The power of accurate observation is frequently called cynicism 
 by those who don't have it."
 -- George Bernard Shaw (1856-1950)