check if array is empty (vba excel)

These if ... then statements are getting the wrong results in my opinion. The first is returning the value 'false' when it should be 'true'. The fourth returns the right value. The second and third return an error.

Sub empty_array() Dim arr1() As Variant If IsEmpty(arr1) Then MsgBox "hey" End If If IsError(UBound(arr1)) Then MsgBox "hey" End If If IsError(Application.match("*", (arr1), 0)) Then MsgBox "hey" End If ReDim arr1(1) arr1(1) = "hey" If IsEmpty(arr1) Then MsgBox "hey" End If End Sub 

13 Answers

Arr1 becomes an array of 'Variant' by the first statement of your code:

Dim arr1() As Variant 

Array of size zero is not empty, as like an empty box exists in real world.

If you define a variable of 'Variant', that will be empty when it is created.

Following code will display "Empty".

Dim a as Variant If IsEmpty(a) then MsgBox("Empty") Else MsgBox("Not Empty") End If 

Adding into this: it depends on what your array is defined as. Consider:

dim a() as integer dim b() as string dim c() as variant 'these doesn't work if isempty(a) then msgbox "integer arrays can be empty" if isempty(b) then msgbox "string arrays can be empty" 'this is because isempty can only be tested on classes which have an .empty property 'this do work if isempty(c) then msgbox "variants can be empty" 

So, what can we do? In VBA, we can see if we can trigger an error and somehow handle it, for example

dim a() as integer dim bEmpty as boolean bempty=false on error resume next bempty=not isnumeric(ubound(a)) on error goto 0 

But this is really clumsy... A nicer solution is to declare a boolean variable (a public or module level is best). When the array is first initialised, then set this variable. Because it's a variable declared at the same time, if it loses it's value, then you know that you need to reinitialise your array. However, if it is initialised, then all you're doing is checking the value of a boolean, which is low cost. It depends on whether being low cost matters, and if you're going to be needing to check it often.

option explicit 'declared at module level dim a() as integer dim aInitialised as boolean sub DoSomethingWithA() if not aInitialised then InitialiseA 'you can now proceed confident that a() is intialised end sub sub InitialiseA() 'insert code to do whatever is required to initialise A 'e.g. redim a(10) a(1)=123 '... aInitialised=true end sub 

The last thing you can do is create a function; which in this case will need to be dependent on the clumsy on error method.

function isInitialised(byref a() as variant) as boolean isInitialised=false on error resume next isinitialised=isnumeric(ubound(a)) end function 

I may be a bit late, but following simple stuff works with string arrays:

Dim files() As String files = "..." 'assign array If Not Not files Then For i = LBound(files) To UBound(files) 'do stuff, array is not empty Next End If 

That's all the code for this.

@jeminar has the best solution above.

I cleaned it up a bit though.

I recommend adding this to a FunctionsArray module

• isInitialised=false is not needed because Booleans are false when created
• On Error GoTo 0 wrap and indent code inside error blocks similar to with blocks for visibility. these methods should be avoided as much as possible but ... VBA ...

Function isInitialised(ByRef a() As Variant) As Boolean On Error Resume Next isInitialised = IsNumeric(UBound(a)) On Error GoTo 0 End Function 

I would do this as

if isnumeric(ubound(a)) = False then msgbox "a is empty!" 

Above methods didn´t work for me. This did:

 Dim arrayIsNothing As Boolean On Error Resume Next arrayIsNothing = IsNumeric(UBound(YOUR_ARRAY)) And False If Err.Number <> 0 Then arrayIsNothing = True Err.Clear On Error GoTo 0 'Now you can test: if arrayIsNothing then ... 

The problem with VBA is that there are both dynamic and static arrays...

Dynamic Array Example

Dim myDynamicArray() as Variant 

Static Array Example

Dim myStaticArray(10) as Variant Dim myOtherStaticArray(0 To 10) as Variant 

Using error handling to check if the array is empty works for a Dynamic Array, but a static array is by definition not empty, there are entries in the array, even if all those entries are empty.

So for clarity's sake, I named my function "IsZeroLengthArray".

 Public Function IsZeroLengthArray(ByRef subject() As Variant) As Boolean 'Tell VBA to proceed if there is an error to the next line. On Error Resume Next Dim UpperBound As Integer Dim ErrorNumber As Long Dim ErrorDescription As String Dim ErrorSource As String 'If the array is empty this will throw an error because a zero-length 'array has no UpperBound (or LowerBound). 'This only works for dynamic arrays. If this was a static array there 'would be both an upper and lower bound. UpperBound = UBound(subject) 'Store the Error Number and then clear the Error object 'because we want VBA to treat unintended errors normally ErrorNumber = Err.Number ErrorDescription = Err.Description ErrorSource = Err.Source Err.Clear On Error GoTo 0 'Check the Error Object to see if we have a "subscript out of range" error. 'If we do (the number is 9) then we can assume that the array is zero-length. If ErrorNumber = 9 Then IsZeroLengthArray = True 'If the Error number is something else then 9 we want to raise 'that error again... ElseIf ErrorNumber <> 0 Then Err.Raise ErrorNumber, ErrorSource, ErrorDescription 'If the Error number is 0 then we have no error and can assume that the 'array is not of zero-length ElseIf ErrorNumber = 0 Then IsZeroLengthArray = False End If End Function 

I hope that this helps others as it helped me.

I'm using this

If UBound(a) >= 0 Then ' not empty Else ' empty... UBound(a) = -1 End If 

IsEmpty(a) did not work for me... I hate VBA

Dim arr() As Variant Debug.Print IsEmpty(arr) ' False Debug.Print UBound(arr) ' raises error arr = Array() Debug.Print IsEmpty(arr) ' False Debug.Print UBound(arr) ' -1 ReDim Preserve arr(UBound(arr) + 1) arr(UBound(arr)) = "test" Debug.Print IsEmpty(arr) ' False Debug.Print UBound(arr) ' 0 

The below function works for both static and dynamic arrays.

 Function array_Empty(testArr As Variant) As Boolean Dim i As Long, k As Long, flag As Long On Error Resume Next i = UBound(testArr) If Err.Number = 0 Then flag = 0 For k = LBound(testArr) To UBound(testArr) If IsEmpty(testArr(k)) = False Then flag = 1 array_Empty = False Exit For End If Next k If flag = 0 Then array_Empty = True Else array_Empty = True End If End Function 

Here's what I use to check if variable is an array with data in it.

Function dataInArray(arr) As Boolean 'check if there is data in array (return true) or if it is empty (return false) 'note - will return false for strings, integers, empty strings, null values, etc Dim varUbound As Variant dataInArray = False 'if any other variable type, return false If VarType(arr) < 8192 Then Exit Function 'if array initialized as variant (without parenth) it is empty (ie: uninitialized) If IsEmpty(arr) Then Exit Function 'if array initialized as variant (with parenth) it is not empty (it is initialized so isempty returns false) On Error Resume Next varUbound = UBound(arr) If Err.Number = 9 Then GoTo dataInArray_Exit If Not varUbound >= 0 Then GoTo dataInArray_Exit dataInArray = True dataInArray_Exit: Err.Clear On Error GoTo 0 End Function 

All variables in this test function return false.

Sub testArrayFxn() Dim varNoParen As Variant Dim varParen() As Variant Dim strParen() As String Dim intParen() As Integer Dim strNoParen As String Dim intNoParen As Integer Debug.Print ("varNoParen returns " + CStr(dataInArray(varNoParen))) Debug.Print ("varParen returns " + CStr(dataInArray(varParen))) Debug.Print ("strParen returns " + CStr(dataInArray(strParen))) Debug.Print ("intParen returns " + CStr(dataInArray(intParen))) Debug.Print ("strNoParen returns " + CStr(dataInArray(strNoParen))) Debug.Print ("intNoParen returns " + CStr(dataInArray(intNoParen))) End Sub 

this worked for me:

Private Function arrIsEmpty(arr as variant) On Error Resume Next arrIsEmpty = False arrIsEmpty = IsNumeric(UBound(arr)) End Function 

Tente isso:

Function inic(mtz As Variant) As Boolean On Error Resume Next Dim x As Boolean x = UBound(mtz): inic = x End Function ... if inic(mymtz) then debug.print "iniciada" else debug.print "não iniciada" end if 

Here is a simple solution for strings at least:

x = Join(y, "") 'Variable = Join(array,delimiter) as string debug.print x="" 'will be true if string array was blank, false if not.