ismissing

[matje]

Private Sub Command1_Click()
f1
End Sub
Private Sub Command2_Click()
f2
End Sub

Private Sub f1(Optional a As Variant)
MsgBox IsMissing(a)
End Sub

Private Sub f2(Optional a As Integer)
MsgBox IsMissing(a)
End Sub

the function only works with the variant type

is there another way to use this

[veryjonny]

use this:

in the Ismissing function just add this:


if isnumeric(a) then

a=     cstr(a)
end if

'further your code

[alex_read]

FROM MSDN :
IsMissing(argname)
The required argname argument contains the name of an optional Variant procedure argument.

Maybe something like this : (If this doesn't do it, let me know the data type you want other than th variant)

Private Sub f1(Optional a As String) 
    If IsNull(a) Then Msgbox "Not Here"
End Sub

[veryjonny]

Perphaps I am sleepy

[matje]

It doesnt work i changed the code a bit

Private Sub Command1_Click()
f1
End Sub
Private Sub Command2_Click()
f2
End Sub

'Private Sub f1(Optional a As Variant)
' MsgBox IsMissing(a)
'End Sub

Private Sub f1(Optional a As String)
If IsNull(a) Then MsgBox "Not Here"
End Sub

Private Sub f2(Optional a As Integer)
MsgBox TypeName(a)
MsgBox IsNull(a)
If IsNull(a) Then
MsgBox "tis null"
End If
MsgBox IsMissing(a)
End Sub

when i press button 1 the functions should show the msgbox with the text not here but nothing appears ...

[c@lle]

because you are DECLARING the optional variable, it is initialized to its default value.

so if you are using a variant, it can have an 'ismissing' value.

but a string is initialized as "" (empty 'string').

so to check this, instead of 'ismissing' use

if a = "" then
msgbox "is missing"
else
msgbox "is not missing (" & a  & ")"
end if

[alex_read]

That's why I asked the data type - if it's a string, you can check for a vbnullstring value.