Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.basic.visual.misc > #803
| From | "Farnsworth" <nospam@nospam.com> |
|---|---|
| Newsgroups | comp.lang.basic.visual.misc |
| Subject | Re: What is a class? |
| Date | 2012-02-25 23:27 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <jiccbm$f0n$1@speranza.aioe.org> (permalink) |
| References | (3 earlier) <XnsA00492FC86A25auricauricauricauric@88.198.244.100> <m_WdnZ1BdOYv6NTSnZ2dnUVZ_jydnZ2d@giganews.com> <XnsA004CD148B656auricauricauricauric@88.198.244.100> <cLCdnTOc3IH0NdTSnZ2dnUVZ_tudnZ2d@giganews.com> <jicag2$87f$1@dont-email.me> |
"GS" <gs@somewhere.net> wrote in message news:jicag2$87f$1@dont-email.me...
> Jim Mack wrote :
>> What follows from that is that you can't then legitimately test "If x Is
>> Nothing" yourself, because doing so references X, and so creates it...
>> that's how you lose (some) control over object lifetime.
>
> I thought that the object created by "Dim As New" existed until the exit
> from the scope they were created in. So...
>
> In a procedure: (local scope)
> Dim colItems As New Collection
> ..lives for the entire procedure if not explicitly destroyed beforhand.
>
> In a module: (module scope)
> Dim colItems As New Collection
> ..lives for the duration code executes within the module if not explicitly
> destroyed beforhand.
>
> Global scope:
> Dim colItems As New Collection
> ..lives for the entire runtime if not explicitly destroyed beforhand.
Correct, however, with "Dim As New", any checking to see if it's nothing
always creates the instance since you are referencing it. So "If o Is
Nothing" is always False in this case. Example:
Option Explicit
Private Sub Form_Load()
Dim o As New Collection
Debug.Print "o.Count = " & o.Count
Set o = Nothing
If o Is Nothing Then
Debug.Print "o Is Nothing"
Else
Debug.Print "o Is NOT Nothing"
End If
End Sub
Output:
o.Count = 0
o Is NOT Nothing
Case 2: No New keyword at Dim:
Option Explicit
Private Sub Form_Load()
Dim o As Collection
Set o = New Collection
Debug.Print "o.Count = " & o.Count
Set o = Nothing
If o Is Nothing Then
Debug.Print "o Is Nothing"
Else
Debug.Print "o Is NOT Nothing"
End If
End Sub
Output:
o.Count = 0
o Is Nothing
Back to comp.lang.basic.visual.misc | Previous | Next — Previous in thread | Next in thread | Find similar
What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-24 04:02 -0800
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-24 14:06 +0000
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-25 03:07 -0800
Re: What is a class? Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-02-25 14:19 +0100
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-25 21:26 +0000
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-25 18:58 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-25 19:39 -0500
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-26 03:09 +0000
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-25 22:35 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-25 22:55 -0500
Re: What is a class? "Farnsworth" <nospam@nospam.com> - 2012-02-25 23:27 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-26 01:30 -0500
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-26 04:41 +0000
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-25 23:05 -0600
Re: What is a class? "Henning" <computer_hero@coldmail.com> - 2012-02-26 11:24 +0100
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-25 23:03 -0600
Re: What is a class? GS <gs@somewhere.net> - 2012-02-26 01:26 -0500
Re: What is a class? "Stuart McCall" <smccall@myunrealbox.com> - 2012-02-27 04:15 +0000
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-27 00:48 -0600
Re: What is a class? "Mayayana" <mayayana@invalid.nospam> - 2012-02-27 08:57 -0500
Re: What is a class? "Stuart McCall" <smccall@myunrealbox.com> - 2012-02-27 19:19 +0000
Re: What is a class? "Stuart McCall" <smccall@myunrealbox.com> - 2012-02-27 19:12 +0000
Re: What is a class? "Bob Butler" <bob_butler@cox.invalid> - 2012-02-27 06:06 -0800
Re: What is a class? "Stuart McCall" <smccall@myunrealbox.com> - 2012-02-27 19:24 +0000
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 11:01 -0500
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-27 11:07 -0600
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 13:10 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-27 19:09 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 13:29 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 14:43 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-27 22:14 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 16:45 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 18:23 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-27 23:26 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-28 13:54 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-28 08:37 -0500
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-28 09:19 -0600
Re: What is a class? GS <gs@somewhere.net> - 2012-02-28 10:42 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-29 06:47 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-29 09:39 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-29 13:33 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-29 14:43 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-29 21:39 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-29 16:15 -0500
Re: What is a class? Schmidt <sss@online.de> - 2012-02-29 23:20 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-28 00:16 -0500
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-27 13:26 -0500
Re: What is a class? "Stuart McCall" <smccall@myunrealbox.com> - 2012-02-27 19:33 +0000
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-27 15:50 -0500
Re: What is a class? Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-02-26 11:02 +0100
Re: What is a class? GS <gs@somewhere.net> - 2012-02-26 14:23 -0500
Re: What is a class? GS <gs@somewhere.net> - 2012-02-26 17:09 -0500
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-25 22:21 -0600
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-26 04:51 +0000
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-25 23:10 -0600
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-26 04:11 -0800
Re: What is a class? Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-02-26 16:37 +0100
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-26 18:36 +0000
Re: What is a class? ralph <nt_consulting64@yahoo.net> - 2012-02-26 14:11 -0600
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-27 03:11 -0800
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-27 16:33 +0000
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-27 13:33 -0500
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-28 04:07 -0800
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-25 03:33 -0800
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-25 04:19 -0800
Re: What is a class? "Ivar" <ivar.ekstromer000@ntlworld.com> - 2012-02-24 15:15 +0000
Re: What is a class? GS <gs@somewhere.net> - 2012-02-24 14:52 -0500
Re: What is a class? "Ivar" <ivar.ekstromer000@ntlworld.com> - 2012-02-24 23:10 +0000
Re: What is a class? GS <gs@somewhere.net> - 2012-02-24 19:46 -0500
Re: What is a class Way off Topic "Ivar" <ivar.ekstromer000@ntlworld.com> - 2012-02-25 02:20 +0000
Re: What is a class Way off Topic GS <gs@somewhere.net> - 2012-02-25 16:57 -0500
Re: What is a class? Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-02-25 11:36 +0100
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-25 03:35 -0800
Re: What is a class? Jim Mack <no-uce-ube@mdxi.com> - 2012-02-24 15:23 -0500
Re: What is a class? "Auric__" <not.my.real@email.address> - 2012-02-25 01:33 +0000
Re: What is a class? Peter Nolan <peter.nolan40@gmail.com> - 2012-02-25 03:09 -0800
Re: What is a class? "Mayayana" <mayayana@invalid.nospam> - 2012-02-24 20:05 -0500
csiph-web