Can a variable hold 2 values simultaneously - a string value and a numeric?

[MLH]

120 MyString = "How many copies of each letter do you need?"
150 MyVariant = InputBox(MyStri ng, "How Many?", "3")
If MyVariant = "2" Then MsgBox "MyVariant equals the string '2'"
If MyVariant = 2 Then MsgBox "MyVariant also equals the value 2"
160 If MyVariant = "" Then HowManyCopies = 1
170 If Not IsNumeric(MyVar iant) Then HowManyCopies = 1
MsgBox "OK. HowManyCopies has a value of " & CStr(HowManyCop ies)
180 For i = 1 To HowManyCopies
190 DoCmd.OpenRepor t "rptITSnoti ces"
200 Next i

OK, what I'm trying to accomplish with the above code is to
have the user input a NUMBER indicating how many copies
of a report he wants. AND, I am trying to determine whether
the user entered gibberish (IE, "q1w2e3r4t5 ") instead of a
number. AND I'm trying to determine whether the user entered
nothing at all. So, I've dim'd MyString as string and MyVariant as
variant.

So, when I run it and I enter the number 2 at the InputBox prompt,
MyVariant equals BOTH the string "2" and the value 2 when I check
it immediately afterwards. That's very confusing for a single variable
to have 2 values - one numeric and the other a string.

[Thelma Lubkin]

MLH <CR**@NorthStat e.net> wrote:
: 120 MyString = "How many copies of each letter do you need?"
: 150 MyVariant = InputBox(MyStri ng, "How Many?", "3")
: If MyVariant = "2" Then MsgBox "MyVariant equals the string '2'"
: If MyVariant = 2 Then MsgBox "MyVariant also equals the value 2"
: 160 If MyVariant = "" Then HowManyCopies = 1
: 170 If Not IsNumeric(MyVar iant) Then HowManyCopies = 1
: MsgBox "OK. HowManyCopies has a value of " & CStr(HowManyCop ies)
: 180 For i = 1 To HowManyCopies
: 190 DoCmd.OpenRepor t "rptITSnoti ces"
: 200 Next i

: OK, what I'm trying to accomplish with the above code is to
: have the user input a NUMBER indicating how many copies
: of a report he wants. AND, I am trying to determine whether
: the user entered gibberish (IE, "q1w2e3r4t5 ") instead of a
: number. AND I'm trying to determine whether the user entered
: nothing at all. So, I've dim'd MyString as string and MyVariant as
: variant.

: So, when I run it and I enter the number 2 at the InputBox prompt,
: MyVariant equals BOTH the string "2" and the value 2 when I check
: it immediately afterwards. That's very confusing for a single variable
: to have 2 values - one numeric and the other a string.

I have *an opinion* as to why this is, but I will let the experts
tell you the actual situation.

But this input-check seems very incomplete to me: it doesn't check
for negative numbers, nor for large numbers -- surely you don't
mean to allow a print run in the billions. And this is a personal
preference: I would force reinput for an entry like q1w2e3r4t5,
and if for some reason that's not an option, I'd set HowManyCopies to
the original default value, 3.

--thelma

[Steve]

I'm no expert myself but it seems to me that your variant is equating
to the string "2" and the integer 2 because it is a variant. Variants
have to explicit data type (and therefore take up a lot of overhead),
and I would think that Access simply stores the value you assign it (in
this case, 2) and tries to accurately compare it to any data type you
test the value with. For example, if this is correct, Access will try
to cast the variant to a Currency value if you try If
myVariant=myCur rencyValue .

What I would do is get rid of the variant altogether, unless there is
another reason it's there, and stick with the strongly-typed String
variable. After the user inputs the number, do your checks and perhaps
even cast it to an integer. I agree with Thelma that you need to do a
lot more input validation before using the value. One thing you could
do to lower the amount of code you need is to check the length of the
input first. For example, if the user enters more than three
characters, you know it's either a mistake or they're just fooling
around. Then you could check legitimate 3-digit values for negatives,
IsNumeric, etc., as Thelma noted.

[Terry Kreft]

As others have said a variant holds data of any type also VBA will try to
cast the data to the type you want.

So in your example the MyVariant variable can be considered to be equal to
both "2" and 2.

If you are trying to force a number from the user you might look at

Dim intInput as Integer

intInput = Val(InputBox(My String, "How Many?", "3"))

'intInput now contains a number you can then test for special cases e.g.

Select case intInput
case 0
MsgBox "You entered 0 cancelling the operation"
case > 10
MsgBox "You entered more than 10 cancelling the operation"
case else
For i = 1 To HowManyCopies
DoCmd.OpenRepor t "rptITSnoti ces"
Next i
end select

--
Terry Kreft

"MLH" <CR**@NorthStat e.net> wrote in message
news:hr******** *************** *********@4ax.c om...

120 MyString = "How many copies of each letter do you need?"
150 MyVariant = InputBox(MyStri ng, "How Many?", "3")
If MyVariant = "2" Then MsgBox "MyVariant equals the string '2'"
If MyVariant = 2 Then MsgBox "MyVariant also equals the value 2"
160 If MyVariant = "" Then HowManyCopies = 1
170 If Not IsNumeric(MyVar iant) Then HowManyCopies = 1
MsgBox "OK. HowManyCopies has a value of " & CStr(HowManyCop ies)
180 For i = 1 To HowManyCopies
190 DoCmd.OpenRepor t "rptITSnoti ces"
200 Next i

OK, what I'm trying to accomplish with the above code is to
have the user input a NUMBER indicating how many copies
of a report he wants. AND, I am trying to determine whether
the user entered gibberish (IE, "q1w2e3r4t5 ") instead of a
number. AND I'm trying to determine whether the user entered
nothing at all. So, I've dim'd MyString as string and MyVariant as
variant.

So, when I run it and I enter the number 2 at the InputBox prompt,
MyVariant equals BOTH the string "2" and the value 2 when I check
it immediately afterwards. That's very confusing for a single variable
to have 2 values - one numeric and the other a string.

[Randy Harris]

InputBox will always return a string. When you execute "If MyVariant = 2"
Access converts the string to a number to do the comparison. As others have
posted, that is not an effective way to determine if the entered data has a
numeric value.

--
Randy Harris
tech at promail dot com
I'm pretty sure I know everything that I can remember.
"MLH" <CR**@NorthStat e.net> wrote in message
news:hr******** *************** *********@4ax.c om...

120 MyString = "How many copies of each letter do you need?"
150 MyVariant = InputBox(MyStri ng, "How Many?", "3")
If MyVariant = "2" Then MsgBox "MyVariant equals the string '2'"
If MyVariant = 2 Then MsgBox "MyVariant also equals the value 2"
160 If MyVariant = "" Then HowManyCopies = 1
170 If Not IsNumeric(MyVar iant) Then HowManyCopies = 1
MsgBox "OK. HowManyCopies has a value of " & CStr(HowManyCop ies)
180 For i = 1 To HowManyCopies
190 DoCmd.OpenRepor t "rptITSnoti ces"
200 Next i

OK, what I'm trying to accomplish with the above code is to
have the user input a NUMBER indicating how many copies
of a report he wants. AND, I am trying to determine whether
the user entered gibberish (IE, "q1w2e3r4t5 ") instead of a
number. AND I'm trying to determine whether the user entered
nothing at all. So, I've dim'd MyString as string and MyVariant as
variant.

So, when I run it and I enter the number 2 at the InputBox prompt,
MyVariant equals BOTH the string "2" and the value 2 when I check
it immediately afterwards. That's very confusing for a single variable
to have 2 values - one numeric and the other a string.

[David W. Fenton]

MLH <CR**@NorthStat e.net> wrote in
news:hr******** *************** *********@4ax.c om:

So, when I run it and I enter the number 2 at the InputBox prompt,
MyVariant equals BOTH the string "2" and the value 2 when I check
it immediately afterwards. That's very confusing for a single
variable to have 2 values - one numeric and the other a string.

Well, first off, don't use a variant for your input type. If you use
an integer, you can then create an error handler that will return a
useful message for anything that can't be stored in an integer. The
principle here is to *never* use a data type that can hold values
other than the type that you really need.

And why is 2 = 2 and 2 = "2"? Because VBA does a lot of implicit
type coercion. When you ask:

?2="2"

and get back TRUE, what VBA is telling you is that it *can* be true,
i.e., that the value you are comparing can be coerced to a data type
that makes the statement true.

That's not a terribly useful piece of information when you really
want to know that the value really *is* a number. That's why it's
important to never rely on implicit type coercion.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

[Jana]

MLH:

I may be way off base, but maybe it would be easier to use a form with
either a text box format to an integer, or maybe even a combo box with
the values 1 through 10 that would GUARANTEE that you get proper
input...

Just a thought,
Jana

[Dean]

I am MOS certified. Personally I would use a form. In fact, you may
want to reference a table so you can store the value the user used.
Then next time he calls the form, the previous form value will be the
default. Create a table that has only one record, then set your form
not to allow additional records. In turn, you can set validation on
the form if you have a print button.

Also on the form a text box called msg but do not reference a field in
the table.

If Me.count>10 then Me.msg = "Cannot print more than 10 copies"
IF Me.count<1 then me.msg = "Not able to print zero copies"
else Me.Msg = "Printing " & Me.Count &" copies"

Something like that.

[MLH]

I have *an opinion* as to why this is, but I will let the experts
tell you the actual situation.

But this input-check seems very incomplete to me: it doesn't check
for negative numbers, nor for large numbers -- surely you don't
mean to allow a print run in the billions. And this is a personal
preference: I would force reinput for an entry like q1w2e3r4t5,
and if for some reason that's not an option, I'd set HowManyCopies to
the original default value, 3.

--thelma

Yeah, you're right thelma. Its not complete. Dim'd number of copies
as byte - limits copies somewhat.

[Lyle Fairfield]

MLH wrote:

Yeah, you're right thelma. Its not complete.

It's not complete?