Extract Number From String

[collectordave]

Just a quick question in case anyone has done it allready.

I recieve several strings in this format

"abc123ab"
"123bs"

etc

The letters either end can be any letter up to a maximum of three letters per string each end but could be no letters and only the number is significant as it is used to sort a whole structured array.

Is there an easy way to extract just the number into an integer variable?

Regards

CD

[RSBasic]

Code: Select all

EnableExplicit

Procedure.s StringToNumberString(String$)
  Protected a
  Protected CurrentCharacter$
  Protected NumberString$
  
  For a=1 To Len(String$)
    CurrentCharacter$ = Mid(String$, a, 1)
    If Asc(CurrentCharacter$) > 47 And Asc(CurrentCharacter$) < 58
      NumberString$ + CurrentCharacter$
    EndIf
  Next
  
  ProcedureReturn NumberString$
EndProcedure

Debug StringToNumberString("abc0123ab")
Debug StringToNumberString("0123bs")

Or:

Code: Select all

EnableExplicit

Procedure StringToNumber(String$)
  Protected a
  Protected CurrentCharacter$
  Protected NumberString$
  
  For a=1 To Len(String$)
    CurrentCharacter$ = Mid(String$, a, 1)
    If Asc(CurrentCharacter$) > 47 And Asc(CurrentCharacter$) < 58
      NumberString$ + CurrentCharacter$
    EndIf
  Next
  
  ProcedureReturn Val(NumberString$)
EndProcedure

Debug StringToNumber("abc123ab")
Debug StringToNumber("123bs")

\\Edit:
Or you use this RegEx code: (\d+)

Code: Select all

If CreateRegularExpression(0, "(\d+)")
  Dim Result$(0)
  NbFound = ExtractRegularExpression(0, "abc123ab", Result$())
  For k = 0 To NbFound-1
    Debug Result$(k)
  Next
Else
  Debug RegularExpressionError()
EndIf

[collectordave]

Excellent All good

Thanks

CD

[Marc56us]

Other regex

Code: Select all

EnableExplicit

Enumeration 
     #Regex
EndEnumeration

Procedure.i Extract_Number(Str_Input.s)
     CreateRegularExpression(#Regex, "\d+")
     If ExamineRegularExpression(#Regex, Str_Input)
          While NextRegularExpressionMatch(#Regex)
               ProcedureReturn Val(RegularExpressionMatchString(#Regex))
          Wend          
     EndIf
     ; FreeRegularExpression(#Regex) ; Not needed here because working in Procedure will auto free ressources when leave
EndProcedure

Debug Extract_Number("abc123ab")
Debug Extract_Number("123bs")

[nco2k]

@RSBasic
never use a function as the -To- expression. it will be executed every single time:

Code: Select all

Procedure Len2(String$)
  Debug String$
  ProcedureReturn Len(String$)
EndProcedure

For i = 1 To Len2("Test") : Next

Debug "---"

Len2 = Len2("Test")
For i = 1 To Len2 : Next

also iterating through strings like that, is very slow and inefficient. pointers should be a LOT faster:

Code: Select all

Procedure.q StringToNumber(*String.Character)
  Protected Result.q, *Number, Length
  While *String\c
    If *String\c >= '0' And *String\c <= '9'
      If *Number = #False
        *Number = *String
      EndIf
      Length + 1
    ElseIf *Number
      Break
    EndIf
    *String + SizeOf(Character)
  Wend
  If *Number
    Result = Val(PeekS(*Number, Length))
  EndIf
  ProcedureReturn Result
EndProcedure

Debug StringToNumber(@"abc123ab")
Debug StringToNumber(@"123bs")
Debug StringToNumber(@"123")

c ya,
nco2k