Nur Zahlen aus einem String zulassen

[SirThornberry]

dann würde ich es widerum so machen:

Delphi-Quellcode:

function OnlyNumbersInString(aValue: String): String; 
var 
  i, j: integer; 
  aChars : TSetofChars; 
begin 
  aChars := ['0'..'9']; 
  j := 0;
  for i := 1 to Length(aValue) do 
  begin 
    if (aValue[i] in aChars) then 
    begin 
      inc(j);
      aValue[j] := aValue[i];
    end; 
  end; 
  //Variante1
  SetLength(aValue, j);
  result := aValue;
  //Variante2
  result := copy(aValue, 1, j);
end;