RegEx - VBA Finding splitting cell with two Uppercase [duplicate] - regex

Question

I'm new to VBA and would like to seek some help with regards to using RegEx and I hope somehow can enlighten me on what I'm doing wrong. I'm currently trying to split a date into its individual date, month and year, and possible delimiters include "," , "-" and "/".
Function formattedDate(inputDate As String) As String
Dim dateString As String
Dim dateStringArray() As String
Dim day As Integer
Dim month As String
Dim year As Integer
Dim assembledDate As String
Dim monthNum As Integer
Dim tempArray() As String
Dim pattern As String()
Dim RegEx As Object
dateString = inputDate
Set RegEx = CreateObject("VBScript.RegExp")
pattern = "(/)|(,)|(-)"
dateStringArray() = RegEx.Split(dateString, pattern)
' .... code continues
This is what I am currently doing. However, there seems to be something wrong during the RegEx.Split function, as it seems to cause my codes to hang and not process further.
To just confirm, I did something simple:
MsgBox("Hi")
pattern = "(/)|(,)|(-)"
dateStringArray() = RegEx.Split(dateString, pattern)
MsgBox("Bye")
"Hi" msgbox pops out, but the "Bye" msgbox never gets popped out, and the codes further down don't seem to get excuted at all, which led to my suspicion that the RegEx.Split is causing it to be stuck.
Can I check if I'm actually using RegEx.Split the right way? According to MSDN here, Split(String, String) returns an array of strings as well.
Thank you!
Edit: I'm trying not to explore the CDate() function as I am trying not to depend on the locale settings of the user's computer.

Answer 1

To split a string with a regular expression in VBA:
Public Function SplitRe(Text As String, Pattern As String, Optional IgnoreCase As Boolean) As String()
Static re As Object
If re Is Nothing Then
Set re = CreateObject("VBScript.RegExp")
re.Global = True
re.MultiLine = True
End If
re.IgnoreCase = IgnoreCase
re.Pattern = Pattern
SplitRe = Strings.Split(re.Replace(text, ChrW(-1)), ChrW(-1))
End Function
Usage example:
Dim v
v = SplitRe("a,b/c;d", "[,;/]")

Answer 2

Splitting by a regex is definitely nontrivial to implement compared to other regex operations, so I don't blame you for being stumped!
If you wanted to implement it yourself, it helps to know that RegExp objects from Microsoft VBScript Regular Expressions 5.5 have a FirstIndex property and a Length property, such that you can loop through the matches and pick out all the substrings between the end of one match (or the start of the string) and the start of the next match (or the end of the string).
If you don't want to implement it yourself, I've also implemented a RegexSplit UDF using those same RegExp objects on my GitHub.

Answer 3

Quoting an example from the documentation of VbScript Regexp:
https://msdn.microsoft.com/en-us/library/y27d2s18%28v=vs.84%29.aspx
Function SubMatchTest(inpStr)
Dim retStr
Dim oRe, oMatch, oMatches
Set oRe = New RegExp
' Look for an e-mail address (not a perfect RegExp)
oRe.Pattern = "(\w+)#(\w+)\.(\w+)"
' Get the Matches collection
Set oMatches = oRe.Execute(inpStr)
' Get the first item in the Matches collection
Set oMatch = oMatches(0)
' Create the results string.
' The Match object is the entire match - dragon#xyzzy.com
retStr = "Email address is: " & oMatch & vbNewLine
' Get the sub-matched parts of the address.
retStr = retStr & "Email alias is: " & oMatch.SubMatches(0) ' dragon
retStr = retStr & vbNewLine
retStr = retStr & "Organization is: " & oMatch.SubMatches(1) ' xyzzy
SubMatchTest = retStr
End Function
To test, call:
MsgBox(SubMatchTest("Please send mail to dragon#xyzzy.com. Thanks!"))
In short, you need your Pattern to match the various parts you want to extract, with the spearators in between, maybe something like:
"(\d+)[/-,](\d+)[/-,](\d+)"
The whole thing will be in oMatch, while the numbers (\d) will end up in oMatch.SubMatches(0) to oMatch.SubMatches(2).