Проверка переменных и выражений с помощью встроенных функций VBA Excel: IsArray, IsDate, IsEmpty, IsError, IsMissing, IsNull, IsNumeric, IsObject.
Проверка переменных и выражений
Встроенные функции VBA Excel — IsArray, IsDate, IsEmpty, IsError, IsMissing, IsNull, IsNumeric, IsObject — проверяют значения переменных и выражений на соответствие определенному типу данных или специальному значению.
Синтаксис функций для проверки переменных и выражений:
Expression — выражение, переменная или необязательный аргумент для IsMissing.
Все функции VBA Excel для проверки переменных и выражений являются логическими и возвращают значение типа Boolean — True или False.
Функция IsArray
Описание функции
Функция IsArray возвращает значение типа Boolean, указывающее, является ли переменная массивом:
- True — переменная является массивом;
- False — переменная не является массивом.
Пример с IsArray
Sub Primer1() Dim arr1(), arr2(1 To 10), arr3 Debug.Print IsArray(arr1) ‘Результат: True Debug.Print IsArray(arr2) ‘Результат: True Debug.Print IsArray(arr3) ‘Результат: False arr3 = Array(1, 2, 3, 4, 5) Debug.Print IsArray(arr3) ‘Результат: True End Sub |
Как показывает пример, функция IsArray возвращает True и в том случае, если переменная только объявлена как массив, но еще не содержит значений.
Функция IsDate
Описание функции
Функция IsDate возвращает логическое значение, указывающее, содержит ли переменная значение, которое можно интерпретировать как дату:
- True — переменная содержит дату, выражение возвращает дату, переменная объявлена с типом As Date;
- False — в иных случаях.
Пример с IsDate
Sub Primer2() Dim d1 As String, d2 As Date Debug.Print IsDate(d1) ‘Результат: False Debug.Print IsDate(d2) ‘Результат: True d1 = «14.01.2023» Debug.Print IsDate(d1) ‘Результат: True Debug.Print IsDate(Now) ‘Результат: True End Sub |
Функция IsEmpty
Описание функции
Функция IsEmpty возвращает значение типа Boolean, указывающее, содержит ли переменная общего типа (As Variant) значение Empty:
- True — переменная содержит значение Empty;
- False — переменной присвоено значение, отличное от Empty.
Пример с IsEmpty
Sub Primer3() Dim s As String, v As Variant Debug.Print IsEmpty(s) ‘Результат: False Debug.Print IsEmpty(v) ‘Результат: True v = 125 Debug.Print IsEmpty(v) ‘Результат: False Range(«A1»).Clear Debug.Print IsEmpty(Range(«A1»)) ‘Результат: True Range(«A1») = 123 Debug.Print IsEmpty(Range(«A1»)) ‘Результат: False End Sub |
Как видно из примера, функцию IsEmpty можно использовать для проверки ячеек на содержание значения Empty (пустая ячейка общего формата).
Функция IsError
Описание функции
Функция IsError возвращает логическое значение, указывающее, является ли аргумент функции значением ошибки, определенной пользователем:
- True — аргумент функции является значением ошибки, определенной пользователем;
- False — в иных случаях.
Пользователь может определить одну или несколько ошибок для своей процедуры или функции с рекомендациями действий по ее (их) исправлению. Возвращается номер ошибки с помощью функции CVErr.
Пример с IsError
Допустим, пользователь определил, что ошибка №25 означает несоответствие аргумента функции Vkuba числовому формату:
Function Vkuba(x) If IsNumeric(x) Then Vkuba = x ^ 3 Else Vkuba = CVErr(25) End If End Function Sub Primer4() Debug.Print Vkuba(5) ‘Результат: 125 Debug.Print IsError(Vkuba(5)) ‘Результат: False Debug.Print Vkuba(«пять») ‘Результат: Error 25 Debug.Print IsError(Vkuba(«пять»)) ‘Результат: True End Sub |
Функция IsMissing
Описание функции
Функция IsMissing возвращает значение типа Boolean, указывающее, был ли необязательный аргумент типа данных Variant передан процедуре:
- True — если в процедуру не было передано значение для необязательного аргумента;
- False — значение для необязательного аргумента было передано в процедуру.
Пример с IsMissing
Function Scepka(x, Optional y) If Not IsMissing(y) Then Scepka = x & y Else Scepka = x & » (а необязательный аргумент не подставлен)» End If End Function Sub Primer5() Debug.Print Scepka(«Тропинка», » в лесу») ‘Результат: Тропинка в лесу Debug.Print Scepka(«Тропинка») ‘Результат: Тропинка (а необязательный аргумент не подставлен) End Sub |
Функция IsNull
Описание функции
Функция IsNull возвращает логическое значение, указывающее, является ли Null значением переменной или выражения:
- True — значением переменной или выражения является Null;
- False — в иных случаях.
Пример с IsNull
Функция IsNull особенно необходима из-за того, что любое условие с выражением, в которое входит ключевое слово Null, возвращает значение False:
Sub Primer6() Dim Var Var = Null If Var = Null Then Debug.Print Var ‘Результат: «» If Var <> Null Then Debug.Print Var ‘Результат: «» If IsNull(Var) Then Debug.Print Var ‘Результат: Null End Sub |
Функция IsNumeric
Описание функции
Функция IsNumeric возвращает значение типа Boolean, указывающее, можно ли значение выражения или переменной рассматривать как число:
- True — если аргумент функции может рассматриваться как число;
- False — в иных случаях.
Пример с IsNumeric
Sub Primer7() Debug.Print IsNumeric(«3,14») ‘Результат: True Debug.Print IsNumeric(«четыре») ‘Результат: False End Sub |
Функция IsObject
Описание функции
Функция IsObject возвращает логическое значение, указывающее, является ли переменная объектной:
- True — переменная содержит ссылку на объект или значение Nothing;
- False — в иных случаях.
Функция IsObject актуальна для переменных типа Variant, которые могут содержать как ссылки на объекты, так и значения других типов данных.
Пример с IsObject
Sub Primer8() Dim myObj As Object, myVar As Variant Debug.Print IsObject(myObj) ‘Результат: True Debug.Print IsObject(myVar) ‘Результат: False Set myVar = ActiveSheet Debug.Print IsObject(myVar) ‘Результат: True End Sub |
Is it possible to use something with similar functionality as Iferror(value, value_if_error) or Iserror(value) in VBA?
I tried to write:
If IsError(Cells(i, c) / curr) Then
'CODE BLOCK 1
else
'CODE BLOCK 2
end if
But VBA tells me that I have division by zero error when it tries to run the if-statement. It throws me into debug. But this is just the type of thing I want to trigger CODE BLOCK 1!
asked Sep 1, 2013 at 19:48
user1283776user1283776
18.8k43 gold badges135 silver badges267 bronze badges
7
The usual way to handle this would be
i = 0
On Error Resume Next
n = 1 / i
If Err.Number <> 0 Then
'Handle error - code block 1
Err.Clear
On Error GoTo 0
Else
On Error GoTo 0
' No error - code block 2
End If
answered Sep 2, 2013 at 6:37
chris neilsenchris neilsen
52.2k10 gold badges84 silver badges122 bronze badges
You can call all worksheet functions using Application.WorksheetFunction.IsError(args)
You could also try doing the calculation in a cell directly and query it’s value. For example, very hacky:
Sub asdf()
Dim ws As New Worksheet
Set ws = ActiveSheet
Dim i As Double
i = 0
ws.Range("A2").Formula = "=iserror(A1 / " & i & ")"
If ws.Range("A2").Value Then
Debug.Print "Error caught"
Else
Debug.Print "No error"
End If
End Subu
GreenGiant
4,8381 gold badge47 silver badges75 bronze badges
answered Sep 1, 2013 at 19:54
JustinJDaviesJustinJDavies
2,6534 gold badges30 silver badges52 bronze badges
2
Excel VBA ISERROR Function
VBA IsError, the function name itself, sums up the functionality. This function will identify whether or not the value we have supplied is an error value. If the supplied or range reference value is an error value, we will get the result as “TRUE.” If the value is not an error, we will get the result as “FALSE.”
Table of contents
- Excel VBA ISERROR Function
- Examples
- Example #1
- Example #2
- Things to Remember
- Recommended Articles
- Examples
Syntax
The expression is nothing but the value we are testing or the cell reference value or formula expression. And as you can see, the result will be “Boolean.”
Examples
You can download this VBA ISERROR Excel Template here – VBA ISERROR Excel Template
Example #1
We will see a simple example to find whether the value is an error. For example, we have the below value in cell A1.
We will test whether this value is an error value or not.
- Start the macro code.
Code:
Sub IsError_Example1() End Sub
- Declare a variable to store the cell A1 value.
Code:
Sub IsError_Example1() Dim ExpValue As Variant End Sub
- Now, assign the value of cell A1 to this variable in VBA.
Code:
Sub IsError_Example1() Dim ExpValue As Variant ExpValue = Range("A1").Value End Sub
- Now, test whether this variable value is an error or not.
Code:
Sub IsError_Example1() Dim ExpValue As Variant ExpValue = Range("A1").Value IsError (ExpValue) End Sub
- Enclose this result in a message box in VBA.
Code:
Sub IsError_Example1() Dim ExpValue As Variant ExpValue = Range("A1").Value MsgBox IsError(ExpValue) End Sub
Let us run the code and see the result of the ISERROR function.
The result is TRUE because the value in cell A1 is #DIV/0! which is the division error.
Now, we will change the value of cell A1 to “Hello.”
Now run the code and see the result.
So, the result is FALSE now because the value in cell A1 is not the error value.
So, first, we need to understand the error types and why they occur in the Excel worksheet. Below are the detailed error values and explanations.
- #DIV/0: This error occurs when we try to divide the number by zero. This error is called “Division by Zero.”
- #N/A: When you try to fetch the data from different tables, and if it finds no value, then we will get this error, which is called “Not Available.”
- #NAME?: If Excel cannot recognize the formula or name, we will get this error.
- #NULL!: When you specify space between the cell referencesCell reference in excel is referring the other cells to a cell to use its values or properties. For instance, if we have data in cell A2 and want to use that in cell A1, use =A2 in cell A1, and this will copy the A2 value in A1.read more instead of a comma.
- #NUM!: The numerical value supplied to the data isn’t a valid one.
- #VALUE!: When you reference the cell values for mathematical calculations, and if the number format is not correct, we will get this error.
- #REF!: If the cell is a formula, it has cell references. If that referenced cell deletes, then we will get this reference error.
Example #2
Now, look at the below data set.
We need to identify the error values from this list and store the result, either TRUE or FALSE, in the next column.
Since we need to test more than one cell, we need to include this in loops. The below code will identify the error values.
Code:
Sub IsError_Example2() Dim k As Integer For k = 2 To 12 Cells(k, 4).Value = IsError(Cells(k, 3).Value) Next k End Sub
When you run this code, we will get the below result in column 4.
Wherever TRUE is, that value is an error value.
Things to Remember
- The ISERROR function returns the Boolean type result, i.e., TRUE or FALSE.
- It is available as a worksheet function as well as a VBA functionVBA functions serve the primary purpose to carry out specific calculations and to return a value. Therefore, in VBA, we use syntax to specify the parameters and data type while defining the function. Such functions are called user-defined functions.read more.
- It is useful as part of large VBA projects.
- It recognizes only pre-determined error values (Read error type).
Recommended Articles
This article has been a guide to VBA ISERROR. Here, we discuss how the Excel VBA ISERROR function identifies whether the value we have supplied is an error value or not with examples. You can learn more about VBA functions from the following articles: –
- VBA IsDate Function
- IFERROR in VBA
- VBA On Error GoTo
- VBA 1004 Error Example
- VBA Double
In this Article
- VBA Errors Cheat Sheet
- Errors
- VBA Error Handling
- VBA On Error Statement
- On Error GoTo 0
- On Error Resume Next
- Err.Number, Err.Clear, and Catching Errors
- On Error GoTo Line
- VBA IsError
- If Error VBA
- VBA Error Types
- Runtime Errors
- Syntax Errors
- Compile Errors
- Debug > Compile
- OverFlow Error
- Other VBA Error Terms
- VBA Catch Error
- VBA Ignore Error
- VBA Throw Error / Err.Raise
- VBA Error Trapping
- VBA Error Message
- VBA Error Handling in a Loop
- VBA Error Handling in Access
VBA Errors Cheat Sheet
Errors
On Error – Stop code and display error
On Error Goto 0
On Error – Skip error and continue running
On Error Resume Next
On Error – Go to a line of code [Label]
On Error Goto [Label]
Clears (Resets) Error
On Error GoTo –1
Show Error number
MsgBox Err.Number
Show Description of error
MsgBox Err.Description
Function to generate own error
Err.Raise
See more VBA “Cheat Sheets” and free PDF Downloads
VBA Error Handling
VBA Error Handling refers to the process of anticipating, detecting, and resolving VBA Runtime Errors. The VBA Error Handling process occurs when writing code, before any errors actually occur.
VBA Runtime Errors are errors that occur during code execution. Examples of runtime errors include:
- Referencing a non-existent workbook, worksheet, or other object (Run-time Error 1004)
- Invalid data ex. referencing an Excel cell containing an error (Type Mismatch – Run-time Error 13)
- Attempting to divide by zero
VBA On Error Statement
Most VBA error handling is done with the On Error Statement. The On Error statement tells VBA what to do if it encounters an error. There are three On Error Statements:
- On Error GoTo 0
- On Error Resume Next
- On Error GoTo Line
On Error GoTo 0
On Error GoTo 0 is VBA’s default setting. You can restore this default setting by adding the following line of code:
On Error GoTo 0
When an error occurs with On Error GoTo 0, VBA will stop executing code and display its standard error message box.
Often you will add an On Error GoTo 0 after adding On Error Resume Next error handling (next section):
Sub ErrorGoTo0()
On Error Resume Next
ActiveSheet.Shapes("Start_Button").Delete
On Error GoTo 0
'Run More Code
End Sub
On Error Resume Next
On Error Resume Next tells VBA to skip any lines of code containing errors and proceed to the next line.
On Error Resume Next
Note: On Error Resume Next does not fix an error, or otherwise resolve it. It simply tells VBA to proceed as if the line of code containing the error did not exist. Improper use of On Error Resume Next can result in unintended consequences.
A great time to use On Error Resume Next is when working with objects that may or may not exist. For example, you want to write some code that will delete a shape, but if you run the code when the shape is already deleted, VBA will throw an error. Instead you can use On Error Resume Next to tell VBA to delete the shape if it exists.
On Error Resume Next
ActiveSheet.Shapes("Start_Button").Delete
On Error GoTo 0
Notice we added On Error GoTo 0 after the line of code containing the potential error. This resets the error handling.
In the next section we’ll show you how to test if an error occurred using Err.Number, giving you more advanced error handling options.
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Err.Number, Err.Clear, and Catching Errors
Instead of simply skipping over a line containing an error, we can catch the error by using On Error Resume Next and Err.Number.
Err.Number returns an error number corresponding with the type of error detected. If there is no error, Err.Number = 0.
For example, this procedure will return “11” because the error that occurs is Run-time error ’11’.
Sub ErrorNumber_ex()
On Error Resume Next
ActiveCell.Value = 2 / 0
MsgBox Err.Number
End Sub
Error Handling with Err.Number
The true power of Err.Number lies in the ability to detect if an error occurred (Err.Number <> 0). In the example below, we’ve created a function that will test if a sheet exists by using Err.Number.
Sub TestWS()
MsgBox DoesWSExist("test")
End Sub
Function DoesWSExist(wsName As String) As Boolean
Dim ws As Worksheet
On Error Resume Next
Set ws = Sheets(wsName)
'If Error WS Does not exist
If Err.Number <> 0 Then
DoesWSExist = False
Else
DoesWSExist = True
End If
On Error GoTo -1
End Function
Note: We’ve added a On Error GoTo -1 to the end which resets Err.Number to 0 (see two sections down).
With On Error Resume Next and Err.Number, you can replicate the “Try” & “Catch” functionality of other programming languages.
On Error GoTo Line
On Error GoTo Line tells VBA to “go to” a labeled line of code when an error is encountered. You declare the Go To statement like this (where errHandler is the line label to go to):
On Error GoTo errHandler
and create a line label like this:
errHandler:
Note: This is the same label that you’d use with a regular VBA GoTo Statement.
Below we will demonstrate using On Error GoTo Line to Exit a procedure.
On Error Exit Sub
You can use On Error GoTo Line to exit a sub when an error occurs.
You can do this by placing the error handler line label at the end of your procedure:
Sub ErrGoToEnd()
On Error GoTo endProc
'Some Code
endProc:
End Sub
or by using the Exit Sub command:
Sub ErrGoToEnd()
On Error GoTo endProc
'Some Code
GoTo skipExit
endProc:
Exit Sub
skipExit:
'Some More Code
End Sub
Err.Clear, On Error GoTo -1, and Resetting Err.Number
After an error is handled, you should generally clear the error to prevent future issues with error handling.
After an error occurs, both Err.Clear and On Error GoTo -1 can be used to reset Err.Number to 0. But there is one very important difference: Err.Clear does not reset the actual error itself, it only resets the Err.Number.
What does that mean? Using Err.Clear, you will not be able to change the error handling setting. To see the difference, test out this code and replace On Error GoTo -1 with Err.Clear:
Sub ErrExamples()
On Error GoTo errHandler:
'"Application-defined" error
Error (13)
Exit Sub
errHandler:
' Clear Error
On Error GoTo -1
On Error GoTo errHandler2:
'"Type mismatch" error
Error (1034)
Exit Sub
errHandler2:
Debug.Print Err.Description
End Sub
Typically, I recommend always using On Error GoTo -1, unless you have a good reason to use Err.Clear instead.
VBA On Error MsgBox
You might also want to display a Message Box on error. This example will display different message boxes depending on where the error occurs:
Sub ErrorMessageEx()
Dim errMsg As String
On Error GoTo errHandler
'Stage 1
errMsg = "An error occured during the Copy & Paste stage."
'Err.Raise (11)
'Stage 2
errMsg = "An error occured during the Data Validation stage."
'Err.Raise (11)
'Stage 3
errMsg = "An error occured during the P&L-Building and Copy-Over stage."
Err.Raise (11)
'Stage 4
errMsg = "An error occured while attempting to log the Import on the Setup Page"
'Err.Raise (11)
GoTo endProc
errHandler:
MsgBox errMsg
endProc:
End Sub
Here you would replace Err.Raise(11) with your actual code.
VBA IsError
Another way to handle errors is to test for them with the VBA ISERROR Function. The ISERROR Function tests an expression for errors, returning TRUE or FALSE if an error occurs.
Sub IsErrorEx()
MsgBox IsError(Range("a7").Value)
End Sub
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If Error VBA
You can also handle errors in VBA with the Excel IFERROR Function. The IFERROR Function must be accessed by using the WorksheetFunction Class:
Sub IfErrorEx()
Dim n As Long
n = WorksheetFunction.IfError(Range("a10").Value, 0)
MsgBox n
End Sub
This will output the value of Range A10, if the value is an error, it will output 0 instead.
VBA Error Types
Runtime Errors
As stated above:
VBA Runtime Errors are errors that occur during code execution. Examples of runtime errors include:
- Referencing a non-existent workbook, worksheet, or other object
- Invalid data ex. referencing an Excel cell containing an error
- Attempting to divide by zero
You can “error handle” runtime errors using the methods discussed above.
Syntax Errors
VBA Syntax Errors are errors with code writing. Examples of syntax errors include:
- Mispelling
- Missing or incorrect punctuation
The VBA Editor identifies many syntax errors with red highlighting:
The VBA Editor also has an option to “Auto Syntax Check”:
When this is checked, the VBA Editor will generate a message box alerting you syntax errors after you enter a line of code:
I personally find this extremely annoying and disable the feature.
Compile Errors
Before attempting to run a procedure, VBA will “compile” the procedure. Compiling transforms the program from source code (that you can see) into executable form (you can’t see).
VBA Compile Errors are errors that prevent the code from compiling.
A good example of a compile error is a missing variable declaration:
Other examples include:
- For without Next
- Select without End Select
- If without End If
- Calling a procedure that does not exist
Syntax Errors (previous section) are a subset of Compile Errors.
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Debug > Compile
Compile errors will appear when you attempt to run a Procedure. But ideally, you would identify compile errors prior to attempting to run the procedure.
You can do this by compiling the project ahead of time. To do so, go to Debug > Compile VBA Project.
The compiler will “go to” the first error. Once you fix that error, compile the project again. Repeat until all errors are fixed.
You can tell that all errors are fixed because Compile VBA Project will be grayed out:
OverFlow Error
The VBA OverFlow Error occurs when you attempt to put a value into a variable that is too large. For example, Integer Variables can only contain values between -32,768 to 32,768. If you enter a larger value, you’ll receive an Overflow error:
Instead, you should use the Long Variable to store the larger number.
Other VBA Error Terms
VBA Catch Error
Unlike other programming languages, In VBA there is no Catch Statement. However, you can replicate a Catch Statement by using On Error Resume Next and If Err.Number <> 0 Then. This is covered above in Error Handling with Err.Number.
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VBA Ignore Error
To ignore errors in VBA, simply use the On Error Resume Next statement:
On Error Resume Next
However, as mentioned above, you should be careful using this statement as it doesn’t fix an error, it just simply ignores the line of code containing the error.
VBA Throw Error / Err.Raise
To through an error in VBA, you use the Err.Raise method.
This line of code will raise Run-time error ’13’: Type mismatch:
Err.Raise (13)
VBA Error Trapping
VBA Error Trapping is just another term for VBA Error Handling.
VBA Error Message
A VBA Error Message looks like this:
When you click ‘Debug’, you’ll see the line of code that is throwing the error:
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VBA Error Handling in a Loop
The best way to error handle within a Loop is by using On Error Resume Next along with Err.Number to detect if an error has occurred (Remember to use Err.Clear to clear the error after each occurrence).
The example below will divide two numbers (Column A by Column B) and output the result into Column C. If there’s an error, the result will be 0.
Sub test()
Dim cell As Range
On Error Resume Next
For Each cell In Range("a1:a10")
'Set Cell Value
cell.Offset(0, 2).Value = cell.Value / cell.Offset(0, 1).Value
'If Cell.Value is Error then Default to 0
If Err.Number <> 0 Then
cell.Offset(0, 2).Value = 0
Err.Clear
End If
Next
End Sub
VBA Error Handling in Access
All of the above examples work exactly the same in Access VBA as in Excel VBA.
Function DelRecord(frm As Form)
'this function is used to delete a record in a table from a form
On Error GoTo ending
With frm
If .NewRecord Then
.Undo
Exit Function
End If
End With
With frm.RecordsetClone
.Bookmark = frm.Bookmark
.Delete
frm.Requery
End With
Exit Function
ending:
End
End Function
Hi all,
I´m trying to build in an error check for a simple macro that will clear all filters. For this I created a Userform, added some bottons, assigned the relevant Makros to them and Bob´s your Unlcle.
Works great bu then I noticed if I don´t have any filters set and click the «Clear Filter» button, it throws me an error.
So I´m trying to catch and test for the error and in the event that it happens, it should just jump to the end of the makro.
Makro used to be this
Code:
Sub RemFilter()
ActiveSheet.ShowAllData
End Sub
Now I´m trying to cathc the error and thought this should work, but it doesnt
Code:
Sub RemFilter()
If Not IsError(ActiveSheet.ShowAllData) Then
ActiveSheet.ShowAllData
Else
End If
End Sub
Any suggestions ? The error code is 1004