[fpc-devel] comparing methods

[Nino Luciani]

On Thursday 10 September 2009 17:52:44 Florian Klaempfl wrote:
> Ivo Steinmann schrieb:
> > 1. Using =nil or Assigned should result in the same.
>
> Afaik not, this was one of the reasons for assigned.
>

I have always used Assigned() to test whether a pointer is 'valid' or is nil. 
Thus Assiged() should return False if pointer is nil?


procedure Test;
var
  myPtr : PChar;

begin
  // Pointer variables are not set to nil by default
  if Assigned(myPtr) then 
    ShowMessage('myPtr is not nil')
  else
    ShowMessage('myPtr is nil');

  // So we must set them to nil to be sure that they are undefined
  myPtr := Nil;
  if Assigned(myPtr) then 
   ShowMessage('myPtr is still not nil')
  else
   ShowMessage('myPtr is nil');
end;

if you don't agree, don't blame me.
http://www.delphibasics.co.uk/RTL.asp?Name=Assigned
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