Manipulates String with VBA - string

Question

I am trying to analyze a String with VBA code.
I read a String that looks like that :
myStringInput = "FRAG_INST = someValue,DR = otherValue, FRAG = anotherValue"
And in my code I would like to associate some variable according to the value read in the string, I would like to initialize my variables like that :
Dim dr, frag, fraginst As String
fraginst = someValue
dr = otherValue
frag = anotherValue
I have tried things like Trim/Split/InStr combination but I always ended up with wrong values.
I cannot just use "Mid" function because length of the values mays change from one execution to another...
To be clearer, I need to design function like this
fraginst = NiceFunction("FRAG_INST",myStringInput)
and it would return "someValue"
Is there an easy way to do what I want ?
Thanks

Answer 1

This solution is working fine. May be you can try this. I have not used any Regular expressions though.
Approach:
I first splitted the string by delimiter ,(comma). Traversed through each of the array elements and splitted each element by '='. Compared the value to the string present on the left side of '=' and returned value to the right of '=' after trimming. Mid function was needed.
myStringInput = "FRAG_INST = someValue,DR = otherValue, FRAG = anotherValue"
fraginst = NiceFunction("FRAG_INST",myStringInput)
MsgBox fraginst
Function NiceFunction(str1, str2)
tempArr1 = Split(str2,",")
For i=0 To UBound(tempArr1)
tempArr2 = Split(tempArr1(i),"=")
If StrComp(Trim(tempArr2(0)),str1,1)=0 Then
NiceFunction = Trim(tempArr2(1))
Exit For
End If
Next
End Function

Answer 2

Function NiceFunction( varName, inputString )
Dim match
With CreateObject("VBScript.RegExp")
.IgnoreCase = True
.Global = False
.Pattern = "(?:^|,)\s*" & varName & "\s*=\s*([^,]*)"
For Each match in .Execute( inputString )
NiceFunction = match.subMatches.Item(0)
Next
End With
End Function
You can use a RegExp object to extract the part of the string you need.

Answer 3

Instead of insisting on 'single' variables (DR, ...) which would need the dynamic creation of variables at run-time, you should use a dictionary:
Option Explicit
Function s2d(s)
If IsEmpty(gR) Then
Set gR = New RegExp
gR.Global = True
gR.Pattern = "(\w+)\s?=\s?(\w+)"
End If
Set s2d = CreateObject("Scripting.Dictionary")
Dim m
For Each m In gR.Execute(s)
If s2d.Exists(m.SubMatches(0)) Then
' Error: dup key
Else
s2d.Add m.SubMatches(0), m.SubMatches(1)
End If
Next
End Function
Function qq(s)
qq = """" & s & """"
End Function
Dim gR ' "static" in s2d()
Dim s : s = "FRAG_INST = someValue,DR = otherValue, FRAG = anotherValue"
If 0 < WScript.Arguments.Count Then s = WScript.Arguments(0)
Dim d : Set d = s2d(s)
Dim k
For Each k In d.Keys()
WScript.Echo qq(k), "=>", qq(d(k))
Next
If d.Exists("DR") Then WScript.Echo "DR:", d("DR") ' access 'single' var
Output:
cscript 44282497.vbs
"FRAG_INST" => "someValue"
"DR" => "otherValue"
"FRAG" => "anotherValue"
DR: otherValue
P.S.
I used a RegExp, because variable names must be 'words'/match "\w+" and your sample data values dito, whereas the separators look like a mess/use spaces creatively. See here fore how to use RegExps in VBA.