1   
2   {
3   FreeAndNil(Object) is a good idea, because if you don't nil an object,
4   just free it, and the object stays in scope, you'll get a dangling pointer.
5   Object.Free will only check if the object is nil or not,
6   NOT if it's valid or not!
7   
8   But what do we do if we use a third party component,
9   which may or may not have freed another object???
10  
11  Here is SafeFree: 
12  }
13  
14  procedure SafeFree(var O: TObject);
15  begin
16    try //now do something - ANYTHING that will be caught by try
17         //if the object is invalid
18      O.FieldAddress('7351');
19      //By now we either have a valid object or we went to the except block.
20      FreeAndNil(O);
21    except
22      O := nil;
23    end;
24  end;
25  
26  {
27  In older versions of Delphi, you won't find FreeAndNil, but you can always use this:
28    Object.Free;
29    Object := nil;
30  }
31  
32  Email Address: Support@HeuristicResearch.com