EveryOne I need some esay way to change from integer and string in delphi 7
var
Str:String;
Int:Integer;
// Here what i need to do
Str:='123';
Int:=Str.AsInteger
// or use this
Int:=123;
Str=Int.AsString;
3 Answers
The easiest way is to use these two methods:
IntVal := StrToInt(StrVal); // will throw EConvertError if not an integer
StrVal := IntToStr(IntVal); // will always work
You can also use the more fault-tolerant TryStrToInt (far better than catching EConvertError):
if not TryStrToInt(StrVal, IntVal) then
begin
// error handling
end;
If you want to resort to a default value instead of handling errors explictly you can use:
IntVal := StrToIntDef(StrVal, 42); // will return 42 if StrVal cannot be converted
Comments
If you're using a recent version of Delphi, in addition to the previous answers, you can alternatively use a pseudo-OOP syntax as you wanted to originally - the naming convention is just ToXXX not AsXXX:
Int := Str.ToInteger
Str := Int.ToString;
The Integer helper also adds Parse and TryParse methods:
Int := Integer.Parse(Str);
if Integer.TryParse(Str, Int) then //...
7 Comments
David Heffernan
Why do you say "pseudo" here? It looks pretty plain OOP syntax to me.
Chris Rolliston
I meant to the extent strings and integers remain not objects in any proper OOP sense (there's no inheritance etc.)
David Heffernan
I would not say that inheritance is needed for OOP. Consider a value type to be a sealed class.
Andriy M
@DavidHeffernan: There wouldn't have been any
Create to either Str or Int, though. Implicit instantiation? Well, whatever. :)David Heffernan
@AndriyM
std::string str; |
You can use:
StrToInt(s)
and
IntToStr(i)
functions.
1 Comment
thank you but i dont need as that ...! look this exsample.
type TForm1 = class(TForm) Button1: TButton; Edit1: TEdit; procedure Button1Click(Sender: TObject); end; Integer = class FValue: System.Integer; function ToString: string; public property Value: System.Integer read FValue write FValue; end; var Form1: TForm1; implementation function Integer.ToString: string; begin Str(FValue, Result); end; procedure TForm1.Button1Click(Sender: TObject); var op:integer; begin op.Value:=45; Edit1.Text:=op.ToString; end; end.
StrToIntfunction, for safe casting e.g.TryStrToInt.StrToIntDef