EXCEL VBA如何使用函数和拆分从字符串中提取整数

Question

I'm working on a piece of code to extract the nominal size of a pipeline from it's tagname. For example: LP-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?

Answer 1

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 [AZ] 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

Answer 2

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