Searching a string for numbers including decimals in VBA - string

Question

So I'm working on a project that has inputs from a fairly clunky database that I have zero control over what type of data it gives me. It basically gives me a string that has numbers in it including decimals.
"take 0.5 Tab by mouth 2 times daily."
Whenever it says tab I want to grab the number before tab and convert it to double format. I know how to use cdbl to convert it once I have the string "0.5" but how I get just that string is kind of difficult since InStr only searches left to right. My thought was to use InStr to find the space before the number that comes before the word "tab" but I'm having trouble figuring out how to code it. Any suggestions?

Answer 1

InStrRev searches right to left. Alternatively, you can use StrReverse and work with the output, but I would use VBScript.Regexp:
Dim text As String
text = "take 0.5 Tab by mouth 2 times daily"
Dim regex As Object
Set regex = CreateObject("VBScript.Regexp")
regex.Global = True
regex.Pattern = "[\d\.]+(?=\sTab)"
Dim test As Object
Set test = regex.Execute(text)
MsgBox (test(0).Value)

Answer 2

Update using Tab as relevant indicator
Assuming that Tab is the relevant indicator you could do the follwing:
Sub ExtractElement()
' column 4 and row 6 contains the text "take 0.5 Tab by mouth 2 times daily"
s = Cells(6, 4).Value
' split text into array for each space
sAr = Split(s, " ")
' iterate over each element of array
For i = 0 To UBound(sAr) - 1
' if the array element "Tab" is reached
If sAr(i) = "Tab" Then
' write the previous array element into the next column
Cells(6, 5).Value = sAr(i-1)
End If
Next
End Sub
Beware that each word is really seperated by a " ". I copied your text and noticed that "Tab by" was not seperated.
Sub ExtractCharCode()
s = Cells(7, 4).Value
For i = 1 To Len(s)
Cells(i, 8).Value = Mid(s, i, 1)
Cells(i, 9).Value = Asc(Mid(s, i, 1))
Next
End Sub
Update using a variation of the answer from user matzone
Instead of passing a range into the function from matzone i would only pass the Value and add a trim to it
Public Function TakeBeforeTab2(s As String) As String
s = Mid(s, 1, InStr(UCase(s), "TAB") - 1)
TakeBeforeTab2 = Trim(Mid(s, InStr(s, " ") + 1))
End Function

Answer 3

To get "0.5" from "take 0.5 Tab by mouth 2 times daily."
Public Function TakeBeforeTab(r As Range) As String
Dim s As String
s = r.Value
s = Mid(s, 1, InStr(UCase(s), "TAB") - 2)
TakeBeforeTab = Mid(s, InStr(s, " ") + 1)
End Function