How to declare static variables in Delphi 2009?

Question

I googled,I binged,I already have seen the other "duplicates" here,but none of them work in Delphi 2009 updated up to update 4.

Like in C#,I want to make a static variable in on line or as short as possible.In the end it works like a global variable,but its sorted.

What's the shortest way to do this in delphi 2009?

EDIT

I followed some of your answers,but it doesn't work.

type:

type
TmyClass = class(TObject)
  var staticVar:integer;
end;

code:

procedure TForm1.Button1Click(Sender: TObject);
var a:integer;
begin
  TMyClass.staticVar := 5; // Line 31
  a := TMyClass.staticVar; // Line 32
  MessageBox(0,IntToStr(a),'',0);
end;

I get the following errors:

[DCC Error] Unit1.pas(31): E2096 Method identifier expected 

[DCC Error] Unit1.pas(32): E2096 Method identifier expected

And on which scope level do you want to declare your static variable? Function level? Class level? Unit level? — jpfollenius
– jpfollenius, Commented Jul 8, 2009 at 6:24
edn.embarcadero.com/article/34324 .This here is what I want.Look at the static methods example."TMyClass.X := 17" is what I want to use without the need to create an instance of the class.However,it doesn't work for me in delphi 2009.I get syntax errors — Ivan Prodanov
– Ivan Prodanov, Commented Jul 8, 2009 at 6:36
Maybe it would help if you showed what you did and what the error is. — Lars Truijens
– Lars Truijens, Commented Jul 8, 2009 at 6:48
If you're getting syntax errors, then it's because you did something wrong. Go back and look at the example again from the article you cited. It is correct. — Rob Kennedy
– Rob Kennedy, Commented Jul 8, 2009 at 6:57

Lars Truijens · Accepted Answer · 2009-07-08 06:57:16Z

18

type
  TMyClass = class(TObject)
  private
    class var FX: Integer;
  public
    class property X: Integer read FX write FX;
  end;

or shorter if you don't use a property

type
  TMyClass = class(TObject)
  public
    class var X: Integer;
  end;

edit: Note the class in class var. You forgot that part.

edited Jul 8, 2009 at 6:57

answered Jul 8, 2009 at 6:39

Lars Truijens

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3 Comments

Ivan Prodanov Over a year ago

I edited my question so you can see my code.I get error when uing your code.

skamradt Over a year ago

You can also specify a default value for the property.

Lars Truijens Over a year ago

You could, but it won't do you any good unless it is in the published section and you also set the default value in the constructor and you use streaming and since it is a static/class property streaming is of no use. :)

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