Re: Has a TStringlist been created

J French wrote:
> On Sat, 14 Oct 2006 07:20:43 +1300, Nicholas Sherlock
> <N.sherlock@[EMAIL PROTECTED]
> wrote:
> 
>> J French wrote:
>>> Well, I used to use the:   If Assigned( SomeObj ) Then   approach
>>> - but I found that I was having to make darn sure that I was doing
>>> SomeObj := Nil   at the begining of the routine because local
>>> variables are not cleared when put on the Stack (except when they are
>>> <g> )
> 
>> But doesn't this just translate to being darn sure that you set your 
>> flag correctly? What is the advantage?
> 
> Well the Flag is quite oviously a Flag, while the 4 byte Object
> pointer is a potential Object - but it is also being used as a Flag

I still don't see the advantage. I do something like this:

var myobj:TObject;

Initialization:

myobj:=nil;

some time later..

myobj:=TObject.create;

some time later..

If assigned(myobj) then use it, otherwise don't.

still later...

FreeAndNil(myobj);

You are recommending something like this:

var
  myobj:TObject;
  objvalid:boolean;

Initialization:

objvalid:=false;

some time later..

myobj:=TObject.create;
objvalid:=true;

some time later..

If objvalid then use it, otherwise don't.

still later...

myobj.free;
objvalid:=false;

What is the advantage?

Cheers,
Nicholas Sherlock

-- 
http://www.sherlocksoftware.org