IsNull Function in Microsoft Excel

The Excel IsNullFunction is used to determine whether or not a variable has a value assigned or not.

The Basics:

 True/False = IsNull(Variable)


Dim variableToEvaluate As Variant
variableToEvaluate = Null

If IsNull(variableToEvaluate) Then MsgBox "The variable variableToEvaluate has no assigned value"


Note: An effective way to evaluate if a value has been assigned to any variable is to use the following command len(trim(Variable))>0. No matter what type of variable is used if it contains a value this function will identify it.


'Declare variables
Dim StringToProcess As String'Variable string to process
Dim arrValues() As String'String Array
Dim A, B As Long
'Value to use as a counter
Dim tmpValue As Variant
Dim Check As Boolean

StringToProcess = ActiveSheet.Cells(2, 1).Value 'Assign the information to process to our variable

arrValues() = Split(StringToProcess, " ") 'Parse the string into a string array using a space delimiter
Counter = 5
For A = LBound(arrValues) To UBound(arrValues)
	Check = IsNumeric(arrValues(A))
	If Check Then
		ActiveSheet.Cells(Counter, 1).Value = CDbl(arrValues(A))
		Counter = Counter + 1
	End If