function StrIsReal(AString: string): Boolean;
var
I: Extended;
Code: Integer;
begin
Val(AString, I, Code);
Result := Code = 0;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Edit1.Text := '123.222';
if StrIsReal(Edit1.Text) then
ShowMessage('Valid float number! Gültige Gleitkommazahl!');
end;
// In Delphi 6, there is a TryStrToFloat function
// In Delphi6 gibt's auch eine TryStrToFloat Funktion
procedure TForm1.Button1Click(Sender: TObject);
var
s: string;
f: double;
begin
s := '123.222';
if TryStrToFloat(s, f) then
ShowMessage('Ok!')
else
ShowMessage('No valid float number!');
end;