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...validate a float number?
Autor: Thomas Stutz
[ Print tip ]  

Tip Rating (8):  
     


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;

 

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