IsMissing Function

Syntax:

IsMissing(expr)

Group:

Variable Info

Description: Returns the True if Optional parameter expr  does not have a defaultvalue and it did not get a value. An Optional parameter may be omitted in the Sub, Function or Property call.

Parameters:

Parameter	Description
expr	Return True if this variant parameter's argument expression was not specified in the Sub, Function or Property call.

Example:

Sub Main
  Opt 'IsMissing(A)=True
  Opt "Hi" 'IsMissing(A)=False
  Many 'No args
  Many 1,"Hello" 'A(0)=1 A(1)=Hello
  OptBye '"Bye"
  OptBye "No" '"No"
EndSub

Sub Opt(Optional A)
  Debug.Print "IsMissing(A)=";IsMissing(A)
EndSub

Sub Many(ParamArray A())
  IfLBound(A) > UBound(A) Then
  Debug.Print "No args"
  Else
  For I = LBound(A) To UBound(A)
  Debug.Print "A(" & I & ")=" & A(I) & " ";
  Next I
  Debug.Print
  EndIf
EndSub

Sub OptBye(Optional A As String = "Bye")
  Debug.Print A
EndSub