[fpc-pascal] splitting string into array

Michael Van Canneyt michael at freepascal.org
Wed Jul 11 12:09:40 CEST 2007



On Tue, 10 Jul 2007, Marc Santhoff wrote:

> Am Dienstag, den 10.07.2007, 14:56 +0200 schrieb Andrea Mauri:
> > I used this, check it.
> > 
> > // Returns an array with the parts of "str" separated by "separator"
> > function Split(const str: string; const separator: string): array of string;
> > var
> >   i, n: integer;
> >   strline, strfield: string;
> > begin
> >   n:= Occurs(str, separator);
> >   SetLength(Result, n + 1);
> >   i := 0;
> >   strline:= str;
> >   repeat
> >     if Pos(separator, strline) > 0 then
> >     begin
> >       strfield:= Copy(strline, 1, Pos(separator, strline) - 1);
> >       strline:= Copy(strline, Pos(separator, strline) + 1, 
> > Length(strline) - pos(separator,strline));
> >     end
> >     else
> >     begin
> >       strfield:= strline;
> >       strline:= '';
> >     end;
> >     Result[i]:= strfield;
> >     Inc(i);
> >   until strline= '';
> >   if Result[High(Result)] = '' then SetLength(Result, Length(Result) -1);
> > end;      
>  
> Pretty cool, thank you very much.
> 
> > andrea
> > 
> > Wolfram Kl├Ąger ha scritto:
> > > Here is a Delphi implementation of the common PHP function 'explode'.
> > >
> > > http://www.michael-puff.de/Developer/Delphi/Code-Snippets/Explode.html
> 
> I'll look at that one, too. Maybe someday my arrays grow and speed
> becomes an issue - better to check which one is fastest.
> 
> Wouldn't this function be a candidate for crawling into the 'strutils'
> unit?

Probably, but I would change the interface:

function Split(const str: string; const separator: string; var Res : array of string) : Integer;

So the function returns the number of elements in the array. 
The function could also use some speedup. Deleting the parts 
which are no longer needed causes a lot of memory fragmentation.

Michael.


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