whats new ¦  programming tips ¦  indy articles ¦  intraweb articles ¦  informations ¦  links ¦  interviews
 misc ¦  tutorials ¦  Add&Win Game

Tips (1541)

Database (90)
Files (137)
Forms (107)
Graphic (114)
IDE (21)
Indy (5)
Internet / LAN (130)
IntraWeb (0)
Math (76)
Misc (126)
Multimedia (45)
Objects/
ActiveX (51)

OpenTools API (3)
Printing (35)
Strings (83)
System (266)
VCL (242)

Top15

Tips sort by
component


Search Tip

Add new Tip

Add&Win Game

Advertising

54 Visitors Online


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

Tip Rating (10):  
     


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;

 

Rate this tip:

poor
very good


Copyright © by SwissDelphiCenter.ch
All trademarks are the sole property of their respective owners