[Gambas-user] Print SizeOf(t) 't is a string

[Tobias Boege]

On Wed, 29 Jul 2015, nando wrote:
> Dim t As String
> 
> Print SizeOf(t)
> Type mismatch: wanted integer, got string instead
> 
> 'Sizeof also errors on a Stucture
> 
> Ubuntu 14.04LTS 
> Gambas 3.7.1
> 

Do you realise that you were replying to a totally unrelated thread from
July 2013? Create a new thread (by writing a new mail instead of replying
to another one) next time.

The documentation[0] of SizeOf clearly states:

   Size = SizeOf ( Datatype )

   Return the memory used for storing a specific datatype.

   Datatype can be one of the following constant:

   Datatype Constant
   Boolean  gb.Boolean
   Byte     gb.Byte
   Short    gb.Short
   Integer  gb.Integer
   [...]

If you want to know how many bytes a string variable takes, you have to use

  SizeOf(gb.String)

but note that this returns the memory usage of the String datatype
(container) not any actual value. On my system SizeOf(gb.String) is 8 bytes,
for the pointer which references the actual string data container in the
interpreter. Doesn't sound very useful and really isn't :-)

The only possible use of SizeOf() which I can think of is when you want to
invoke libc's qsort() for a Gambas array (you get the datatype constant from
Array.Type).

Needless to say, SizeOf() cannot be used to measure the size a Struct would
take up on your system. You could maybe use SizeOf() on its contents...

Regards,
Tobi

[0] http://gambaswiki.org/wiki/lang/sizeof

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk