StrToUInt64

[himitsu]

Mit ist/war es so, als wenn es mit Val ging ... kann aber auch nur eine Sinnestäuschung/Gedächtnisstörung sein

Delphi-Quellcode:

var
  i: UInt64;
  e: Integer;
begin
  Val('10376293541461622783', i, e);
  if i = 1037629354146162278 then
    ShowMessage('falsch');
  if i = $8FFFFFFFFFFFFFFF then
    ShowMessage('richtig');

  Val('$8FFFFFFFFFFFFFFF', i, e);
  if i = $8FFFFFFFFFFFFFFF then
    ShowMessage('richtig');
end;

'n alter Code von mir

Delphi-Quellcode:

Function fromStr(Const S: AnsiString; Out i: LargeWord; Default: LargeWord = 0): ByteBool;
  Var P: Integer;

  Begin
    P := 1;
    While (P <= _Length(S)) and (S[P] <= ' ') do Inc(P);
    Result := (P <= _Length(S)) and (S[P] in ['0'..'9']);
    While (P <= _Length(S)) and (S[P] in ['0'..'9', scThousandSeparator]) do Inc(P);
    While (P <= _Length(S)) and (S[P] <= ' ') do Inc(P);
    Result := Result and (P > _Length(S));
    If Result Then Begin
      i := 0;
      P := 1;
      While P <= _Length(S) do Begin
        If S[P] in ['0'..'9'] Then Begin
          If (i > 1844674407370955161) or ((i = 1844674407370955161) and ((Byte(S[P]) xor $30) > 5)) Then Begin
            i := Default;
            Result := False;
            Exit;
          End;
          i := i * 10 + (Byte(S[P]) xor $30);
        End;
        Inc(P);
      End;
    End Else i := Default;
  End;

[edit]
gekürzt sieht es wohl in etwa so aus:

Delphi-Quellcode:

Function StrToUInt64(Const S: String; Out i: UInt64; Default: UInt64 = 0): Boolean;
  Var P: Integer;

  Begin
    P := 1;
    Result := (P <= Length(S)) and (S[P] >= '0') and (S[P] <= '9');
    While (P <= Length(S)) and (S[P] >= '0') and (S[P] <= '9') do Inc(P);
    Result := Result and (P > Length(S));
    If Result Then Begin
      i := 0;
      P := 1;
      While P <= Length(S) do Begin
        If (i > 1844674407370955161) or ((i = 1844674407370955161) and (Ord(S[P]) - Ord('0') > 5)) Then Begin
          i := Default;
          Result := False;
          Exit;
        End;
        i := i * 10 + Ord(S[P]) - Ord('0');
        Inc(P);
      End;
    End Else i := Default;
  End;