Simple Arrays

[Roy Riddex]

2nd post of the day! I'm just learning about Arrays at College and have met
a problem. I have 5 text boxes for number input, a command button to add the
numbers to the array, and a command button which displays the array contents
in 5 labels. My program works fine. The problem is that I use a simple If
statement to check for any empty boxes. I've to cut the IF statement and use
a For Each...Next statement to check for empty text boxes but I'm struggling
to apply this method. The book also tells me to declare a variable 'Dim
MyTextBox As TextBox', I've never came across this variable type before.
I'll post my working version of the program and hopefully someone can help
me out.

Option Explicit

Dim Numbers(1 To 5) As Integer

Private Sub cmdAddToArray_C lick()
Dim Index As Integer
If (txtNumbers(1). Text = "") Or (txtNumbers(2). Text = "") Or
(txtNumbers(3). Text = "") Or (txtNumbers(4). Text = "") Or
(txtNumbers(5). Text = "") Then
MsgBox "You have not entered 5 numbers"
Else
For Index = 1 To 5
Numbers(Index) = txtNumbers(Inde x).Text
Next Index
End If
End Sub

Private Sub cmdDisplayArray _Click()
Dim Index As Integer
For Index = 1 To 5
lblNumbers(Inde x).Caption = Numbers(Index)
Next Index
End Sub

[Randy Birch]

Re: Simple Arrays

off the top of my head ...

dim ctl as textbox

for each ctl in me

if typeof ctl is textbox then

if len(ctl.text) = 0 then
msgbox "what part of 'enter 5 numbers' don't you understand?"
ctl.setfocus
exit for
end if
end if
next ctl

--

Randy Birch
MVP Visual Basic

http://www.mvps.org/vbnet/

Please respond only to the newsgroups so all can benefit.


"Roy Riddex" <roy_riddexNOSP AM@blueyonder.c o.uk> wrote in message
news:f68Cb.2994 7$kh4.13863@new s-binary.blueyond er.co.uk...
: 2nd post of the day! I'm just learning about Arrays at College and have
met
: a problem. I have 5 text boxes for number input, a command button to add
the
: numbers to the array, and a command button which displays the array
contents
: in 5 labels. My program works fine. The problem is that I use a simple If
: statement to check for any empty boxes. I've to cut the IF statement and
use
: a For Each...Next statement to check for empty text boxes but I'm
struggling
: to apply this method. The book also tells me to declare a variable 'Dim
: MyTextBox As TextBox', I've never came across this variable type before.
: I'll post my working version of the program and hopefully someone can help
: me out.
:
: Option Explicit
:
: Dim Numbers(1 To 5) As Integer
:
: Private Sub cmdAddToArray_C lick()
: Dim Index As Integer
: If (txtNumbers(1). Text = "") Or (txtNumbers(2). Text = "") Or
: (txtNumbers(3). Text = "") Or (txtNumbers(4). Text = "") Or
: (txtNumbers(5). Text = "") Then
: MsgBox "You have not entered 5 numbers"
: Else
: For Index = 1 To 5
: Numbers(Index) = txtNumbers(Inde x).Text
: Next Index
: End If
: End Sub
:
: Private Sub cmdDisplayArray _Click()
: Dim Index As Integer
: For Index = 1 To 5
: lblNumbers(Inde x).Caption = Numbers(Index)
: Next Index
: End Sub
:
:

[Mauro]

Re: Simple Arrays

Of course, since ctl was declared as TextBox, no other object really should
be enumerated in the loop, so the line 'if typeof ctl is textbox then' could
really be dropped. However, if you were enumerating all objects and
declared ctl as object, then it would be necessary.


Mauro


"Randy Birch" <rgb_removethis @mvps.org> wrote in message
news:qv9Cb.3030 7$VEd1.7852@new s02.bloor.is.ne t.cable.rogers. com...[color=blue]
> off the top of my head ...
>
> dim ctl as textbox
>
> for each ctl in me
>
> if typeof ctl is textbox then
>
> if len(ctl.text) = 0 then
> msgbox "what part of 'enter 5 numbers' don't you understand?"
> ctl.setfocus
> exit for
> end if
> end if
> next ctl
>
> --
>
> Randy Birch
> MVP Visual Basic
> http://www.mvps.org/vbnet/
> Please respond only to the newsgroups so all can benefit.
>
>
> "Roy Riddex" <roy_riddexNOSP AM@blueyonder.c o.uk> wrote in message
> news:f68Cb.2994 7$kh4.13863@new s-binary.blueyond er.co.uk...
> : 2nd post of the day! I'm just learning about Arrays at College and have
> met
> : a problem. I have 5 text boxes for number input, a command button to add
> the
> : numbers to the array, and a command button which displays the array
> contents
> : in 5 labels. My program works fine. The problem is that I use a simple[/color]
If[color=blue]
> : statement to check for any empty boxes. I've to cut the IF statement and
> use
> : a For Each...Next statement to check for empty text boxes but I'm
> struggling
> : to apply this method. The book also tells me to declare a variable 'Dim
> : MyTextBox As TextBox', I've never came across this variable type before.
> : I'll post my working version of the program and hopefully someone can[/color]
help[color=blue]
> : me out.
> :
> : Option Explicit
> :
> : Dim Numbers(1 To 5) As Integer
> :
> : Private Sub cmdAddToArray_C lick()
> : Dim Index As Integer
> : If (txtNumbers(1). Text = "") Or (txtNumbers(2). Text = "") Or
> : (txtNumbers(3). Text = "") Or (txtNumbers(4). Text = "") Or
> : (txtNumbers(5). Text = "") Then
> : MsgBox "You have not entered 5 numbers"
> : Else
> : For Index = 1 To 5
> : Numbers(Index) = txtNumbers(Inde x).Text
> : Next Index
> : End If
> : End Sub
> :
> : Private Sub cmdDisplayArray _Click()
> : Dim Index As Integer
> : For Index = 1 To 5
> : lblNumbers(Inde x).Caption = Numbers(Index)
> : Next Index
> : End Sub
> :
> :
>
>[/color]

[Bob Butler]

Re: Simple Arrays

"Mauro" <mbiefeni@hotma il.com> wrote in message news:<_8rCb.681 270$pl3.655010@ pd7tw3no>...[color=blue]
> Of course, since ctl was declared as TextBox, no other object really should
> be enumerated in the loop, so the line 'if typeof ctl is textbox then' could
> really be dropped. However, if you were enumerating all objects and
> declared ctl as object, then it would be necessary.[/color]

try it with at least 1 label on the form... the for each construct
enumerates all controls regardless of the declared type of the loop
variable in VB

The only thing I'd change in Randy's code is explicitly stating teh
collection name instead of relying on the default:
For Each ctl In Me.Controls

[Randy Birch]

Re: Simple Arrays

yep .. that's why it was air code. <g>

--

Randy Birch
MVP Visual Basic

http://www.mvps.org/vbnet/

Please respond only to the newsgroups so all can benefit.


"Bob Butler" <butlerbob@eart hlink.net> wrote in message
news:fa10fb0.03 12130828.306539 b1@posting.goog le.com...
: "Mauro" <mbiefeni@hotma il.com> wrote in message
news:<_8rCb.681 270$pl3.655010@ pd7tw3no>...
: > Of course, since ctl was declared as TextBox, no other object really
should
: > be enumerated in the loop, so the line 'if typeof ctl is textbox then'
could
: > really be dropped. However, if you were enumerating all objects and
: > declared ctl as object, then it would be necessary.
:
: try it with at least 1 label on the form... the for each construct
: enumerates all controls regardless of the declared type of the loop
: variable in VB
:
: The only thing I'd change in Randy's code is explicitly stating teh
: collection name instead of relying on the default:
: For Each ctl In Me.Controls

[Steve Gerrard]

Re: Simple Arrays


"Randy Birch" <rgb_removethis @mvps.org> wrote in message
news:pmHCb.1065 6$%TO.9694@twis ter01.bloor.is. net.cable.roger s.com...[color=blue]
> yep .. that's why it was air code. <g>
>[color=green]
>> off the top of my head ...
>>
>> dim ctl as textbox
>>
>> for each ctl in me
>>[/color][/color]

If you declare ctl as TextBox, not Control, shouldn't this code break if
encounters a control that is not a TextBox?

[Rick Rothstein]

Re: Simple Arrays

> > yep .. that's why it was air code. <g>[color=blue][color=green]
> >[color=darkred]
> >> off the top of my head ...
> >>
> >> dim ctl as textbox
> >>
> >> for each ctl in me
> >>[/color][/color]
>
> If you declare ctl as TextBox, not Control, shouldn't this code break if
> encounters a control that is not a TextBox?[/color]

Correct... for the code Randy posted, ctl needs to be declared as a Control.
However, the OP showed that he was using a control array of TextBoxes. That
means, the For Each can be made to enumerate only the control array
elements. Here is Randy's code modified to do that (txtNumbers was the name
of the control array the OP posted)...


Rick - MVP

Private Sub Command1_Click( )

Dim ctl As TextBox

For Each ctl In txtNumbers

If Len(ctl.Text) = 0 Then
MsgBox "What part of 'Enter 5 numbers' don't you understand?"
ctl.SetFocus
Exit For
End If

Next ctl

End Sub

[Roy Riddex]

Re: Simple Arrays

Thanks guys, I'll give it a try.

[Bob Butler]

Re: Simple Arrays

"Rick Rothstein" <rickNOSPAMnews @NOSPAMcomcast. net> wrote in message news:<IsednW_rb 4cRdEaiRVn-vg@comcast.com> ...[color=blue][color=green][color=darkred]
> > > yep .. that's why it was air code. <g>
> > >
> > >> off the top of my head ...
> > >>
> > >> dim ctl as textbox
> > >>
> > >> for each ctl in me
> > >>[/color]
> >
> > If you declare ctl as TextBox, not Control, shouldn't this code break if
> > encounters a control that is not a TextBox?[/color]
>
> Correct... for the code Randy posted, ctl needs to be declared as a Control.[/color]

dang, can't believe I missed that!

[Steve Gerrard]

Re: Simple Arrays


"Rick Rothstein" <rickNOSPAMnews @NOSPAMcomcast. net> wrote in message
news:IsednW_rb4 cRdEaiRVn-vg@comcast.com. ..[color=blue][color=green][color=darkred]
> > > yep .. that's why it was air code. <g>[/color][/color]
>
> Correct... for the code Randy posted, ctl needs to be declared as a[/color]
Control.[color=blue]
> However, the OP showed that he was using a control array of TextBoxes.[/color]
That[color=blue]
> means, the For Each can be made to enumerate only the control array
> elements. Here is Randy's code modified to do that (txtNumbers was the[/color]
name[color=blue]
> of the control array the OP posted)...
>
> Private Sub Command1_Click( )
>
> Dim ctl As TextBox
>
> For Each ctl In txtNumbers
>
> ...[/color]

You know, I am pretty sure I would have tried some sort of For n = 0 to
UBound(txtNumbe rs), but VB won't recognize a control array as an array
in this context. And if I hard code the upper limit, I am still assuming
that the indexes are sequential, which does not have to be the case.
I would not have thought to try a For Each on a control array, which I
like better. Doesn't this all mean that actually what you have is a
collection, not an array?

[Larry Serflaten]

Re: Simple Arrays

"Steve Gerrard" <notstevegerrar d@comcast.net> wrote
[color=blue][color=green]
> > Dim ctl As TextBox
> >
> > For Each ctl In txtNumbers[/color]
>
> You know, I am pretty sure I would have tried some sort of For n = 0 to
> UBound(txtNumbe rs), but VB won't recognize a control array as an array
> in this context. And if I hard code the upper limit, I am still assuming
> that the indexes are sequential, which does not have to be the case.
> I would not have thought to try a For Each on a control array, which I
> like better. Doesn't this all mean that actually what you have is a
> collection, not an array?[/color]


No, you have some unknown hybrid type. Intellisense will list LBound
and UBound as well as Count and Item. LBound and UBound are usually
associated with arrays, but Count and Item are associated with collections.

For the example above, type; txtNumbers.
(Where the list will show up in the code window after you type the dot.)


LFS




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[Randy Birch]

Re: Simple Arrays

sure it will. But since the controls - array or not - are all part of the
Controls collection, For Each can be easier.

--

Randy Birch
MVP Visual Basic

http://www.mvps.org/vbnet/

Please respond only to the newsgroups so all can benefit.


"Steve Gerrard" <notstevegerrar d@comcast.net> wrote in message
news:EKKdnWUaKq N9K0GiRVn-hQ@comcast.com. ..
:
: "Rick Rothstein" <rickNOSPAMnews @NOSPAMcomcast. net> wrote in message
: news:IsednW_rb4 cRdEaiRVn-vg@comcast.com. ..
: > > > yep .. that's why it was air code. <g>
: >
: > Correct... for the code Randy posted, ctl needs to be declared as a
: Control.
: > However, the OP showed that he was using a control array of TextBoxes.
: That
: > means, the For Each can be made to enumerate only the control array
: > elements. Here is Randy's code modified to do that (txtNumbers was the
: name
: > of the control array the OP posted)...
: >
: > Private Sub Command1_Click( )
: >
: > Dim ctl As TextBox
: >
: > For Each ctl In txtNumbers
: >
: > ...
:
: You know, I am pretty sure I would have tried some sort of For n = 0 to
: UBound(txtNumbe rs), but VB won't recognize a control array as an array
: in this context. And if I hard code the upper limit, I am still assuming
: that the indexes are sequential, which does not have to be the case.
: I would not have thought to try a For Each on a control array, which I
: like better. Doesn't this all mean that actually what you have is a
: collection, not an array?
:
:

[Steve Gerrard]

Re: Simple Arrays


"Larry Serflaten" <Abuse@SpamBust ers.com> wrote in message
news:3fdcc276_7 @corp.newsgroup s.com...[color=blue]
> "Steve Gerrard" <notstevegerrar d@comcast.net> wrote[color=green]
> >Doesn't this all mean that actually what you have is a[/color]
> collection, not an array?[/color]
[color=blue]
> No, you have some unknown hybrid type. Intellisense will list LBound
> and UBound as well as Count and Item. LBound and UBound are usually
> associated with arrays, but Count and Item are associated with[/color]
collections.[color=blue]
>
> For the example above, type; txtNumbers.
> (Where the list will show up in the code window after you type the[/color]
dot.)[color=blue]
>
>[/color]

I didn't know that. Interesting that for a control array, UBound is a
method - I think this is the only case where that is true. It still
seems more like a collection to me now, with some array features tacked
on.

[Roy Riddex]

Re: Simple Arrays

Thanks for your help. You all started to get me a wee bit confused, lol. Had
a bit of trouble with the Exit For statement at first, it should have been
Exit Sub.
It works fine now. Below is a code listing. Thanks again.

Dim Numbers(1 To 5) As Integer

Private Sub cmdCheckForBlan ks_Click()
Dim ctl As TextBox
Dim Index As Integer
For Each ctl In txtNumbers
If Len(ctl.Text) = 0 Then
MsgBox "What part of 'enter 5 numbers' don't you understand?"
ctl.SetFocus
Exit Sub
End If
Next ctl
For Index = 1 To 5
Numbers(Index) = txtNumbers(Inde x).Text
Next Index
End Sub

Private Sub cmdDisplayArray _Click()
Dim Index As Integer
For Index = 1 To 5
lblNumbers(Inde x).Caption = Numbers(Index)
Next Index
End Sub