ismissing

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

use this:

Code:

---

in the Ismissing function just add this:


if isnumeric(a) then

a=    cstr(a)
end if

'further your code

---

Quote:

---

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)

Code:

---

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

---

Perphaps I am sleepy:rolleyes: :D

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 ...

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

Code:

---

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

---

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