I'm working on a piece of code to extract the nominal size of a pipeline from it's tagname. For example: L-P-50-00XX-0000-000. The 50 would be it's nominal size (2") which I would like to extract. I know I could do it like this:
TagnameArray() = Split("L-P-50-00XX-0000-000", "-")
DNSize = TagnameArray(2)
But I would like it to be a function because it's a small part of my whole macro and I don't need it for all the plants I'm working on just this one. My current code is:
Sub WBDA_XXX()
Dim a As Range, b As Range
Dim TagnameArray() As String
Dim DNMaat As String
Dim DN As String
Set a = Selection
For Each b In a.Rows
IntRow = b.Row
TagnameArray() = Split(Cells(IntRow, 2).Value, "-")
DN = DNMaat(IntRow, TagnameArray())
Cells(IntRow, 3).Value = DN
Next b
End Sub
Function DNMaat(IntRow As Integer, TagnameArray() As String) As Integer
For i = LBound(TagnameArray()) To UBound(TagnameArray())
If IsNumeric(TagnameArray(i)) = True Then
DNMaat = TagnameArray(i)
Exit For
End If
Next i
End Function
However this code gives me a matrix expected error which I don't know how to resolve. I would also like to use the nominal size in further calculations so it will have to be converted to an integer after extracting it from the tagname. Does anyone see where I made a mistake in my code?
This is easy enough to do with a split, and a little help from the 'Like' evaluation.
A bit of background on 'Like' - It will return TRUE or FALSE based on whether an input variable matches a given pattern. In the pattern [A-Z] means it can be any uppercase letter between A and Z, and # means any number.
The code:
' Function declared to return variant strictly for returning a Null string or a Long
Public Function PipeSize(ByVal TagName As String) As Variant
' If TagName doesn't meet the tag formatting requirements, return a null string
If Not TagName Like "[A-Z]-[A-Z]-##-##[A-Z]-####-###" Then
PipeSize = vbNullString
Exit Function
End If
' This will hold our split pipecodes
Dim PipeCodes As Variant
PipeCodes = Split(TagName, "-")
' Return the code in position 2 (Split returns a 0 based array by default)
PipeSize = PipeCodes(2)
End Function
You will want to consider changing the return type of the function depending on your needs. It will return a null string if the input tag doesnt match the pattern, otherwise it returns a long (number). You can change it to return a string if needed, or you can write a second function to interpret the number to it's length.
Here's a refactored version of your code that finds just the first numeric tag. I cleaned up your code a bit, and I think I found the bug as well. You were declaring DNMAAT as a String but also calling it as a Function. This was likely causing your Array expected error.
Here's the code:
' Don't use underscores '_' in names. These hold special value in VBA.
Sub WBDAXXX()
Dim a As Range, b As Range
Dim IntRow As Long
Set a = Selection
For Each b In a.Rows
IntRow = b.Row
' No need to a middleman here. I directly pass the split values
' since the middleman was only used for the function. Same goes for cutting DN.
' Also, be sure to qualify these 'Cells' ranges. Relying on implicit
' Activesheet is dangerous and unpredictable.
Cells(IntRow, 3).value = DNMaat(Split(Cells(IntRow, 2).value, "-"))
Next b
End Sub
' By telling the function to expect a normal variant, we can input any
' value we like. This can be dangerous if you dont anticipate the errors
' caused by Variants. Thus, I check for Arrayness on the first line and
' exit the function if an input value will cause an issue.
Function DNMaat(TagnameArray As Variant) As Long
If Not IsArray(TagnameArray) Then Exit Function
Dim i As Long
For i = LBound(TagnameArray) To UBound(TagnameArray)
If IsNumeric(TagnameArray(i)) = True Then
DNMaat = TagnameArray(i)
Exit Function
End If
Next i
End Function
The error matrix expected is thrown by the compiler because you have defined DNMaat twice: Once as string variable and once as a function. Remove the definition as variable.
Another thing: Your function will return an integer, but you assigning it to a string (and this string is used just to write the result into a cell). Get rid of the variable DN and assign it directly:
Cells(IntRow, 3).Value = DNMaat(IntRow, TagnameArray())
Plus the global advice to use option explicit to enforce definition of all used variables and to define a variable holding a row/column number always as long and not as integer
I am familiar with this post: How to Return a result from a VBA Function but changing my code does not seem to help.
I want to write a simple function in VBA that allows to lowercase an input sentence. I wrote this:
Private Function Converter(inputText As String) As String
Converter = LCase(inputText)
End Function
Sub test()
Dim new_output As String
new_output = Converter("Henk")
MsgBox (new_output)
End Sub
I tried following the advice I found at another stackoverflow post. I made me change this:
Private Function Converter(inputText As String)
Set outputText = LCase(inputText)
End Function
Sub test()
Dim new_output As String
Set new_output = Converter("Henk")
MsgBox (new_output)
End Sub
However, now I get an error that an object is required. Why does it require an object now? I dont get it...
Set outputText = LCase(inputText)
The Set keyword is reserved for Object data types. Unlike VB.NET, String in VBA is a basic data types.
So you dont Set a variable to a string. Drop the second version of your code altogether. It doesn't make sense. That "advice" was probably in another context.
To fix your first version
1- Assign the returned result to the name of the function Converter
2- It would be beneficial to specify explicitly the return type, as String. Currently it is a Variant that always embeds a String, so better make it explicit:
' vvvvvvvvv
Private Function Converter(inputText As String) As String
Converter = LCase(inputText) ' <------------ assign return to name of function
End Function
I'm writing some VBA functions in Excel that compute word values and cross sums of the input.
I'm passing the input as Public Function cross_sum(myRange As Range) As Integer to them so that they take cell references as input, e.g. =cross_sum(A1). Works fine.
However when I try to chain two functions like =cross_sum(word_value(A1)) I run into th VALUE error because word_value() returns an Integer value and not the Range cross_sum() is set to expect. However I did not find a way to cast an Integer (or String) into a Range.
As Excel's built-in functions support chaining as well as Range input I wonder how.
Unfortunately this is my first VBA project so I wonder if and how to cast or what type to choose to get this working both ways.
Any pointers appreciated!
TIA,
JBQ
You can pass Variant to a function and the function can determine the type of input:
Public Function Inputs(v As Variant) As String
If TypeName(v) = "Range" Then
MsgBox "you gave me a range"
Else
MsgBox "you gave me a string"
End If
Inputs = "done"
End Function
Sub MAIN()
Dim st As String
Dim rng As Range
st = "A1"
Set rng = Range(st)
x = Inputs(st)
x = Inputs(rng)
End Sub
Without your code, it is hard to know what you could change. That being said...
There is not a way to convert an integer to a range. You would have to create a function to do so if that is what you desired.
You could create a converter function, maybe titled IntegerToRange, that takes an integer and after some logic (maybe 1 = "A1", 2 = "A2" or something), will return a range. Your cell formula would then be =cross_sum(IntegerToRange(word_value(A1))
Alternatively, you could modify your word_value function to return a range instead of an integer. Your cell formula would then be =cross_sum(word_value(A1).
I have defined a variable with an own type, say
Dim point As DataPoint
Public Type DataPoint
list as Collection
name as String
number as Integer
End Type
and I want to delete all values of the variable point at once. If it was a class, I would just use Set point = New DataPoint, or set Set point = Nothing, but how can I proceed if it's a type?
You can benefit from the fact that functions in VB have an implicit variable that holds the result, and that contains the default type value by default.
public function GetBlankPoint() as DataPoint
end function
Usage:
point = GetBlankPoint()
The standard way is to reset each member to its default value individually. This is one limitation of user-defined types compared to objects.
At the risk of stating the obvious:
With point
Set .list = Nothing
.name = ""
.number = 0
End With
Alternatively, you can create a "blank" variable and assign it to your variable each time you want to "clear" it.
Dim point As DataPoint
Dim blank As DataPoint
With point
Set .list = New Collection
.list.Add "carrots"
.name = "joe"
.number = 12
End With
point = blank
' point members are now reset to default values
EDIT: Damn! Beaten by JFC :D
Here is an alternative to achieve that in 1 line ;)
Dim point As DataPoint
Dim emptyPoint As DataPoint
Public Type DataPoint
list As Collection
name As String
number As Integer
End Type
Sub Sample()
'~~> Fill the point
Debug.Print ">"; point.name
Debug.Print ">"; point.number
point.name = "a"
point.number = 25
Debug.Print ">>"; point.name
Debug.Print ">>"; point.number
'~~> Empty the point
point = emptyPoint
Debug.Print ">>>"; point.name
Debug.Print ">>>"; point.number
End Sub
SNAPSHOT
One-liner:
Function resetDataPoint() As DataPoint: End Function
Usage:
point = resetDataPoint()
Another option is to use the reserved word "Empty" such as:
.number= Empty
The only issue is that you will need to change the number from integer to variant.
Using classes in VBA is usually a good practice in case it is not a single purpose solution or the class do not contain too many private attributes because if you want to adhere on OOP rules and keep your class safe, you should declare all the Let and Get properties for all private attributes of class. This is too much coding in case you have more than 50 private attributes. Another negative side of using classes in excel is fact, that VBA do not fully support the OOP. There is no polymorfism, overloading, etc.) Even you want to use an inheritance, you have to declare all the attributes and methods from the original class in the inherited class.
So in this case I would prefer the solution suggested by Jean-François Corbett or GSeng, i.e. to assign an empty variable of the same UDT as the variable you want to clear or to use a function which to me seems little bit more elegant solution because it will not reserve permanent memory for the emtpy variable of your UDT type.
For that is better to use classes, you can declare a class module with the name of your type, then declare all of your members as public, then automatically you can set to nothing and new for create and delete instances.
syntax will be somthing like this after you create the class module and named like your type:
'
Public List as Collection
Public Name as String
Public Number as Long
Private Sub Class_Initialize()
'Here you can assign default values for the public members that you created if you want
End Sub
Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
Which features of the VBA language are either poorly documented, or simply not often used?
This trick only works in Access VBA, Excel and others won't allow it. But you can make a Standard Module hidden from the object browser by prefixing the Module name with an underscore. The module will then only be visible if you change the object browser to show hidden objects.
This trick works with Enums in all vb6 based version of VBA. You can create a hidden member of an Enum by encasing it's name in brackets, then prefixing it with an underscore. Example:
Public Enum MyEnum
meDefault = 0
meThing1 = 1
meThing2 = 2
meThing3 = 3
[_Min] = meDefault
[_Max] = meThing3
End Enum
Public Function IsValidOption(ByVal myOption As MyEnum) As Boolean
If myOption >= MyEnum.[_Min] Then IsValidOption myOption <= MyEnum.[_Max]
End Function
In Excel-VBA you can reference cells by enclosing them in brackets, the brackets also function as an evaluate command allowing you to evaluate formula syntax:
Public Sub Example()
[A1] = "Foo"
MsgBox [VLOOKUP(A1,A1,1,0)]
End Sub
Also you can pass around raw data without using MemCopy (RtlMoveMemory) by combining LSet with User Defined Types of the same size:
Public Sub Example()
Dim b() As Byte
b = LongToByteArray(8675309)
MsgBox b(1)
End Sub
Private Function LongToByteArray(ByVal value As Long) As Byte()
Dim tl As TypedLong
Dim bl As ByteLong
tl.value = value
LSet bl = tl
LongToByteArray = bl.value
End Function
Octal & Hex Literals are actually unsigned types, these will both output -32768:
Public Sub Example()
Debug.Print &H8000
Debug.Print &O100000
End Sub
As mentioned, passing a variable inside parenthesis causes it to be passed ByVal:
Sub PredictTheOutput()
Dim i&, j&, k&
i = 10: j = i: k = i
MySub (i)
MySub j
MySub k + 20
MsgBox Join(Array(i, j, k), vbNewLine), vbQuestion, "Did You Get It Right?"
End Sub
Public Sub MySub(ByRef foo As Long)
foo = 5
End Sub
You can assign a string directly into a byte array and vice-versa:
Public Sub Example()
Dim myString As String
Dim myBytArr() As Byte
myBytArr = "I am a string."
myString = myBytArr
MsgBox myString
End Sub
"Mid" is also an operator. Using it you overwrite specific portions of strings without VBA's notoriously slow string concatenation:
Public Sub Example1()
''// This takes about 47% of time Example2 does:
Dim myString As String
myString = "I liek pie."
Mid(myString, 5, 2) = "ke"
Mid(myString, 11, 1) = "!"
MsgBox myString
End Sub
Public Sub Example2()
Dim myString As String
myString = "I liek pie."
myString = "I li" & "ke" & " pie" & "!"
MsgBox myString
End Sub
There is an important but almost always missed feature of the Mid() statement. That is where Mid() appears on the left hand side of an assignment as opposed to the Mid() function that appears in the right hand side or in an expression.
The rule is that if the if the target string is not a string literal, and this is the only reference to the target string, and the length of segment being inserted matches the length of the segment being replaced, then the string will be treated as mutable for the operation.
What does that mean? It means that if your building up a large report or a huge list of strings into a single string value, then exploiting this will make your string processing much faster.
Here is a simple class that benefits from this. It gives your VBA the same StringBuilder capability that .Net has.
' Class: StringBuilder
Option Explicit
Private Const initialLength As Long = 32
Private totalLength As Long ' Length of the buffer
Private curLength As Long ' Length of the string value within the buffer
Private buffer As String ' The buffer
Private Sub Class_Initialize()
' We set the buffer up to it's initial size and the string value ""
totalLength = initialLength
buffer = Space(totalLength)
curLength = 0
End Sub
Public Sub Append(Text As String)
Dim incLen As Long ' The length that the value will be increased by
Dim newLen As Long ' The length of the value after being appended
incLen = Len(Text)
newLen = curLength + incLen
' Will the new value fit in the remaining free space within the current buffer
If newLen <= totalLength Then
' Buffer has room so just insert the new value
Mid(buffer, curLength + 1, incLen) = Text
Else
' Buffer does not have enough room so
' first calculate the new buffer size by doubling until its big enough
' then build the new buffer
While totalLength < newLen
totalLength = totalLength + totalLength
Wend
buffer = Left(buffer, curLength) & Text & Space(totalLength - newLen)
End If
curLength = newLen
End Sub
Public Property Get Length() As Integer
Length = curLength
End Property
Public Property Get Text() As String
Text = Left(buffer, curLength)
End Property
Public Sub Clear()
totalLength = initialLength
buffer = Space(totalLength)
curLength = 0
End Sub
And here is an example on how to use it:
Dim i As Long
Dim sb As StringBuilder
Dim result As String
Set sb = New StringBuilder
For i = 1 to 100000
sb.Append CStr( i)
Next i
result = sb.Text
VBA itself seems to be a hidden feature. Folks I know who've used Office products for years have no idea it's even a part of the suite.
I've posted this on multiple questions here, but the Object Browser is my secret weapon. If I need to ninja code something real quick, but am not familiar with the dll's, Object Browser saves my life. It makes it much easier to learn the class structures than MSDN.
The Locals Window is great for debugging as well. Put a pause in your code and it will show you all the variables, their names, and their current values and types within the current namespace.
And who could forget our good friend Immediate Window? Not only is it great for Debug.Print standard output, but you can enter in commands into it as well. Need to know what VariableX is?
?VariableX
Need to know what color that cell is?
?Application.ActiveCell.Interior.Color
In fact all those windows are great tools to be productive with VBA.
It's not a feature, but a thing I have seen wrong so many times in VBA (and VB6): Parenthesis added on method calls where it will change semantics:
Sub Foo()
Dim str As String
str = "Hello"
Bar (str)
Debug.Print str 'prints "Hello" because str is evaluated and a copy is passed
Bar str 'or Call Bar(str)
Debug.Print str 'prints "Hello World"
End Sub
Sub Bar(ByRef param As String)
param = param + " World"
End Sub
Hidden Features
Although it is "Basic", you can use OOP - classes and objects
You can make API calls
Possibly the least documented features in VBA are those you can only expose by selecting "Show Hidden Members" on the VBA Object Browser. Hidden members are those functions that are in VBA, but are unsupported. You can use them, but microsoft might eliminate them at any time. None of them has any documentation provided, but you can find some on the web. Possibly the most talked about of these hidden features provides access to pointers in VBA. For a decent writeup, check out; Not So Lightweight - Shlwapi.dll
Documented, but perhaps more obscure (in excel anyways) is using ExecuteExcel4Macro to access a hidden global namespace that belongs to the entire Excel application instance as opposed to a specific workbook.
You can implement interfaces with the Implements keyword.
Dictionaries. VBA is practically worthless without them!
Reference the Microsoft Scripting Runtime, use Scripting.Dictionary for any sufficiently complicated task, and live happily ever after.
The Scripting Runtime also gives you the FileSystemObject, which also comes highly recommended.
Start here, then dig around a bit...
http://msdn.microsoft.com/en-us/library/aa164509%28office.10%29.aspx
Typing VBA. will bring up an intellisense listing of all the built-in functions and constants.
With a little work, you can iterate over custom collections like this:
' Write some text in Word first.'
Sub test()
Dim c As New clsMyCollection
c.AddItems ActiveDocument.Characters(1), _
ActiveDocument.Characters(2), _
ActiveDocument.Characters(3), _
ActiveDocument.Characters(4)
Dim el As Range
For Each el In c
Debug.Print el.Text
Next
Set c = Nothing
End Sub
Your custom collection code (in a class called clsMyCollection):
Option Explicit
Dim m_myCollection As Collection
Public Property Get NewEnum() As IUnknown
' This property allows you to enumerate
' this collection with the For...Each syntax
' Put the following line in the exported module
' file (.cls)!'
'Attribute NewEnum.VB_UserMemId = -4
Set NewEnum = m_myCollection.[_NewEnum]
End Property
Public Sub AddItems(ParamArray items() As Variant)
Dim i As Variant
On Error Resume Next
For Each i In items
m_myCollection.Add i
Next
On Error GoTo 0
End Sub
Private Sub Class_Initialize()
Set m_myCollection = New Collection
End Sub
Save 4 whole keystrokes by typing debug.? xxx instead of debug.print xxx.
Crash it by adding: enum foo: me=0: end enum to the top of a module containing any other code.
Support for localized versions, which (at least in the previous century) supported expressions using localized values. Like Pravda for True and Fałszywy (not too sure, but at least it did have the funny L) for False in Polish... Actually the English version would be able to read macros in any language, and convert on the fly. Other localized versions would not handle that though.
FAIL.
The VBE (Visual Basic Extensibility) object model is a lesser known and/or under-utilized feature. It lets you write VBA code to manipulate VBA code, modules and projects. I once wrote an Excel project that would assemble other Excel projects from a group of module files.
The object model also works from VBScript and HTAs. I wrote an HTA at one time to help me keep track of a large number of Word, Excel and Access projects. Many of the projects would use common code modules, and it was easy for modules to "grow" in one system and then need to be migrated to other systems. My HTA would allow me to export all modules in a project, compare them to versions in a common folder and merge updated routines (using BeyondCompare), then reimport the updated modules.
The VBE object model works slightly differently between Word, Excel and Access, and unfortunately doesn't work with Outlook at all, but still provides a great capability for managing code.
IsDate("13.50") returns True but IsDate("12.25.2010") returns False
This is because IsDate could be more precisely named IsDateTime. And because the period (.) is treated as a time separator and not a date separator. See here for a full explanation.
VBA supports bitwise operators for comparing the binary digits (bits) of two values. For example, the expression 4 And 7 evaluates the bit values of 4 (0100) and 7 (0111) and returns 4 (the bit that is on in both numbers.) Similarly the expression 4 Or 8 evaluates the bit values in 4 (0100) and 8 (1000) and returns 12 (1100), i.e. the bits where either one is true.
Unfortunately, the bitwise operators have the same names at the logical comparison operators: And, Eqv, Imp, Not, Or, and Xor. This can lead to ambiguities, and even contradictory results.
As an example, open the Immediate Window (Ctrl+G) and enter:
? (2 And 4)
This returns zero, since there are no bits in common between 2 (0010) and 4 (0100).
Deftype Statements
This feature exists presumably for backwards-compatibility. Or to write hopelessly obfuscated spaghetti code. Your pick.