When an Excel file with a macro is opened, do all the
forms and the controls on the forms exist before the form
is initialized or called? The reason I am asking is that
I was recently using the value of a form's checkbox
instead of a boolean variable to control an IF statement.
It seems to work just as well either way, but I decided
that it might be dangerous to assume that the form's
checkbox is true or false or even that the form exists
before being called, so I created an explicit boolean
variable and made it public. What's the best practice?

Start,

Don't rely on it. It doesn't exist on the workbook opening, but when you
reference it, it is loaded into memory. Loading initialises all controls,
etc. So a checkbox is initialised to whatever the design sets it at. A
variable is the same problem, re-opening the workbook will initialise.

The safest places are the registry, stored in a file, or a workbook name.

--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Stratuser" wrote in message
...
When an Excel file with a macro is opened, do all the
forms and the controls on the forms exist before the form
is initialized or called? The reason I am asking is that
I was recently using the value of a form's checkbox
instead of a boolean variable to control an IF statement.
It seems to work just as well either way, but I decided
that it might be dangerous to assume that the form's
checkbox is true or false or even that the form exists
before being called, so I created an explicit boolean
variable and made it public. What's the best practice?

You can be guaranteed a newly-declared boolean variable will have a
value that coerces to false i.e.

Sub test()
Dim blnTest As Boolean
Debug.Print blnTest ' returns false
Debug.Print blnTest = Empty ' returns true
Debug.Print IsEmpty(blnTest) ' returns false
End Sub

But best practise is to never use a *public* variable.

--

"Stratuser" wrote in message ...
When an Excel file with a macro is opened, do all the
forms and the controls on the forms exist before the form
is initialized or called? The reason I am asking is that
I was recently using the value of a form's checkbox
instead of a boolean variable to control an IF statement.
It seems to work just as well either way, but I decided
that it might be dangerous to assume that the form's
checkbox is true or false or even that the form exists
before being called, so I created an explicit boolean
variable and made it public. What's the best practice?