FirstDelimiter Delphi Function

_{Submitted by Jens Borrisholt}

In the RTL there's a LastDelimiter function which returns the index of the last occurence in a string of the characters cpecified.

What about the first delimiter - a function that would return the index of the first occurence in a string of the characters cpecified.

FirstDelimiter

Here's the function returning the index of the first character in a string specified by a set of characters - delimiters:

function FirstDelimiter(const Delimiters, S: string): Integer;

var

  P, Q: PChar;

  Len : Integer;

begin

  Result := 0;

  P := Pointer(Delimiters) ;

  Q := Pointer(s) ;

  Len := StrLen(Q) ;

  while Result < Len do

    if (Q[Result] <> #0) and (StrScan(P, Q[Result]) <> nil) then

      Exit

    else

      Inc(Result) ;

end;

Usage example:

//handles Edit1's OnChange event - gets the index of the first number character in a string

procedure TForm1.Edit1Change(Sender: TObject) ;

var

  s : String;

  i : Integer;

begin

 i := FirstDelimiter('0123456789', (Sender as TEdit).Text) ;

 Caption := Copy((Sender as TEdit).Text, 1, i) ;

end;

Delphi tips navigator:
» Delphi Project Structure Folder Organisation - Best Practice in How to Layout Delphi Project Files
« Prevent the System from Entering Sleep or Turning off the Display while your Delphi Application is Running