[fpc-pascal] Initialize object variables

[Darius Blaszyk]

Is there any way to initialize object variables, other than writing an init 
method?

So something like:

myobj = object
   myvar: word = $;
end;

Regards, Darius___
fpc-pascal maillist  -  fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

Re: [fpc-pascal] Initialize object variables

[Jürgen Hestermann]

Darius Blaszyk schrieb:

Is there any way to initialize object variables, other than writing an init 
method?
So something like:
myobj = object
   myvar: word = $;
end;
  

I don't think so.
An object is a pointer to a data structure on the heap.
At compile time, this data structure is not yet allocated.

___
fpc-pascal maillist  -  fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

Re: [fpc-pascal] Initialize object variables

[Howard Page-Clark]

On 28/4/11 10:00, Jürgen Hestermann wrote:



Darius Blaszyk schrieb:

Is there any way to initialize object variables, other than writing an
init method?
So something like:
myobj = object
myvar: word = $;
end;

I don't think so.
An object is a pointer to a data structure on the heap.
At compile time, this data structure is not yet allocated.

___
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

I think objects are allocated on the stack (not the heap), but that does 
not help in circumventing the init method to initialize them.


Howard
___
fpc-pascal maillist  -  fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

Re: [fpc-pascal] Initialize object variables

[Sven Barth]

Am 28.04.2011 11:33, schrieb Howard Page-Clark:

On 28/4/11 10:00, Jürgen Hestermann wrote:



Darius Blaszyk schrieb:

Is there any way to initialize object variables, other than writing an
init method?
So something like:
myobj = object
myvar: word = $;
end;

I don't think so.
An object is a pointer to a data structure on the heap.
At compile time, this data structure is not yet allocated.

___
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal


I think objects are allocated on the stack (not the heap), but that does
not help in circumventing the init method to initialize them.


Yes, they are on the stack and yes that makes a difference:

=== source begin ===

type
  TMyObject = object
i: Integer;
s: String;
  end;

procedure Test;
var
  a: TMyObject = (
   i: 42;
   s: 'Foo';
begin
  Writeln(a.i);
  Writeln(a.s);
end;

=== source end ===

A call to "Test" will print

=== output begin ===
42
Foo
=== output end ===

This works with records (and primitive types) as well (it does not work 
in Delphi though as Delphi does not allow initialization of local variables)


Regards,
Sven
___
fpc-pascal maillist  -  fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal