Scope chain of JScript Functions

re: Scope chain of JScript Functions

Vishal Gupta — Mon, 12 Apr 2010 06:03:05 GMT

Hey, I like the article, but I would appreciate if you could clarify the following. So, is there a two way link between the activation objects and the global object? There has to be a link(pointer) from the activation objects towards the global object for scope resolution. But is there also a link the other way around? Because, you mentioned, when function returns, the global object doesn't point to the activation object anymore and therefore it is garbage collected. Also, does this also mean that any object that doesn't have a link(pointer) from the global object is garbage collected? I would appreciate if you could help clarify these doubts. Thanks again!

re: Scope chain of JScript Functions

Paul Podlipensky — Sat, 23 Jan 2010 22:37:56 GMT

I'm wondering about JScript.NET private variables. Please take a look on the following code:

import System;

import System.Windows.Forms;

import System.Drawing;

var jsPDF = function(){

var state = 0;

var beginPage = function(){

state = 2;

out('beginPage');

}

var out = function(text){

if(state == 2){

var st = 3;

}

MessageBox.Show(text + ' ' + state);

}

var addHeader = function(){

out('header');

}

return {

endDocument: function(){

state = 1;

addHeader();

out('endDocument');

beginDocument: function(){

beginPage();

}

var j = new jsPDF();

j.beginDocument();

j.endDocument();

Output:

beginPage 2

header 2

endDocument 2

if I run the same script in any browser, the output is:

beginPage 2

header 1

endDocument 1

Why it is so??

Thanks,

Paul.

re: Scope chain of JScript Functions

Venu — Wed, 06 May 2009 12:43:00 GMT

Nice explanation. Thanks a lot.

re: Scope chain of JScript Functions

sam — Mon, 17 Mar 2008 09:08:21 GMT

It's a shame that I can't see the image.

re: Scope chain of JScript Functions

-TNO- — Thu, 13 Mar 2008 13:52:41 GMT

Don't forget this design and how it corresponds to prototype:

var Foo = (function(){...})();

re: Scope chain of JScript Functions

shivaram.p — Fri, 25 Jan 2008 11:54:52 GMT

Você é bem-vindo (You are welcome)

re: Scope chain of JScript Functions

Marcos Remar — Wed, 23 Jan 2008 20:00:13 GMT

Muito bom seu artigo. Foi de grande ajuda. Portuguese(Brazil)

good!

re: Scope chain of JScript Functions

Webhosting — Sat, 19 Jan 2008 16:15:38 GMT

very detailed article. This really helped me clarify some doubts. One quick question, does all of it apply to JavaScript in general or some of it is specific to Microsoft's implementation of JavaScript?

Lastly, I expect to see few more of this knowledge based article in future.

re: Scope chain of JScript Functions

shivaram.p — Mon, 06 Aug 2007 11:56:34 GMT

Thanks for your comments. You can expect more such articles in future. All the scope chain stuff explained in this article is in general.

re: Scope chain of JScript Functions

Kim — Sun, 29 Jul 2007 07:58:43 GMT

A very detailed article. This really helped me clarify some doubts. One quick question, does all of it apply to JavaScript in general or some of it is specific to Microsoft's implementation of JavaScript?

Lastly, I expect to see few more of this knowledge based article in future.