Comments on: with Statement Considered Harmful http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/ News and Artilces about Designing and Developing with Yahoo! Libraries. Mon, 12 May 2008 09:48:09 +0000 http://wordpress.org/?v=2.3.3 By: Kevin Greer http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-364807 Kevin Greer Thu, 01 May 2008 17:24:13 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-364807 This also works: <code> with ({o:ooo.eee.oo.ah_ah.ting.tang.walla.walla}) { o.bing = true; o.bang = true; } </code> but reads a little nicer and limits the scope of 'o'. This also works:


with ({o:ooo.eee.oo.ah_ah.ting.tang.walla.walla})
{
o.bing = true;
o.bang = true;
}

but reads a little nicer and limits the scope of ‘o’.

]]> By: Helping the YUI Compressor » Yahoo! User Interface Blog http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-302591 Helping the YUI Compressor » Yahoo! User Interface Blog Mon, 11 Feb 2008 14:01:42 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-302591 [...] with statement is another that is often recommended to avoid in JavaScript. For YUI Compressor, the reason is the same for eval(): just the presence of with in a function [...] […] with statement is another that is often recommended to avoid in JavaScript. For YUI Compressor, the reason is the same for eval(): just the presence of with in a function […]

]]> By: O “with” em linguagens de programação « blog http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-159545 O “with” em linguagens de programação « blog Sat, 21 Jul 2007 02:36:10 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-159545 [...] C++, porém o estilo Pascal não é recomendado, por causa da natureza dinâmica da linguagem (with-statement-considered-harmful). Como propriedades podem ser adicionadas livremente aos objetos e variáveis globais podem ser [...] […] C++, porém o estilo Pascal não é recomendado, por causa da natureza dinâmica da linguagem (with-statement-considered-harmful). Como propriedades podem ser adicionadas livremente aos objetos e variáveis globais podem ser […]

]]> By: .wpal » Blog Archives » зло with http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-151412 .wpal » Blog Archives » зло with Tue, 03 Jul 2007 13:47:15 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-151412 [...] бы всё хорошо и удобно. Но вот мне на глаза попалась статья на YUI-блоге, которую и попробую [...] […] бы всё хорошо и удобно. Но вот мне на глаза попалась статья на YUI-блоге, которую и попробую […]

]]> By: David Holmes http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-144116 David Holmes Thu, 21 Jun 2007 08:49:33 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-144116 Responding to myself, to save anyone else the trouble : I have come to the realization that the above pattern is indeed very common. One can encounter it in the YUI code for example, and I have seen it called a "Crockford Module pattern". So, tricky, but very useful ! Responding to myself, to save anyone else the trouble :

I have come to the realization that the above pattern is indeed very common. One can encounter it in the YUI code for example, and I have seen it called a “Crockford Module pattern”.

So, tricky, but very useful !

]]> By: David Holmes http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-137198 David Holmes Thu, 07 Jun 2007 20:38:33 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-137198 Mr. Crockford, you propose a new snippet in your last comment, which is equivalent to : (function () { var o = ... o.foo = ... o.bar = ... })(); Thank you for posting it, I was missing the parens around the function statement when I came up with it, and without them the snippet does not work. (I wonder why, actually ?) However you call that snippet "tricky". Did you mean to be disparaging, or was it irony ? Because it seems to me that it is the ideal way of implementing your suggestion from the article without polluting the global namespace with the temporary shortcut variables. Mr. Crockford, you propose a new snippet in your last comment, which is equivalent to :

(function () {
var o = …
o.foo = …
o.bar = …
})();

Thank you for posting it, I was missing the parens around the function statement when I came up with it, and without them the snippet does not work. (I wonder why, actually ?)

However you call that snippet “tricky”. Did you mean to be disparaging, or was it irony ? Because it seems to me that it is the ideal way of implementing your suggestion from the article without polluting the global namespace with the temporary shortcut variables.

]]> By: Seth Flowers http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-125883 Seth Flowers Thu, 24 May 2007 14:49:28 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-125883 Douglas, explain the advantage of using your suggestion of: (function (Dom, Event) { // my program here… }) (YAHOO.util.Dom, YAHOO.util.Event); over Isaac's suggestion of: with ({ Dom:YAHOO.util.Dom, Event:YAHOO.util.Event }) { // my program here… } They appear functionally and semantically equivalent. Douglas, explain the advantage of using your suggestion of:

(function (Dom, Event) {

// my program here…

}) (YAHOO.util.Dom, YAHOO.util.Event);

over Isaac’s suggestion of:

with ({
Dom:YAHOO.util.Dom,
Event:YAHOO.util.Event
}) {

// my program here…

}

They appear functionally and semantically equivalent.

]]> By: I’d Rather switch Than Fight! » Yahoo! User Interface Blog http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-114652 I’d Rather switch Than Fight! » Yahoo! User Interface Blog Tue, 15 May 2007 05:02:57 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-114652 [...] they encourage weak coding patterns. JavaScript has more than its share of attractive nuisances (with, implied globals, new, and semicolon insertion, to name a few). Your programs will be stronger if [...] […] they encourage weak coding patterns. JavaScript has more than its share of attractive nuisances (with, implied globals, new, and semicolon insertion, to name a few). Your programs will be stronger if […]

]]> By: Douglas Crockford http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-31477 Douglas Crockford Sat, 13 Jan 2007 00:28:21 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-31477 You don't need with there, either. It is better to use vars in a function. If you want something trickier just to be tricker, try this: (function (Dom, Event) { // my program here... }) (YAHOO.util.Dom, YAHOO.util.Event); You don’t need with there, either. It is better to use vars in a function. If you want something trickier just to be tricker, try this:

(function (Dom, Event) {

// my program here…

}) (YAHOO.util.Dom, YAHOO.util.Event);

]]> By: Schlueterica » Lessons in Javascript Optimization http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-31443 Schlueterica » Lessons in Javascript Optimization Fri, 12 Jan 2007 22:25:42 +0000 http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-31443 [...] Normally, the with statement is a pretty bad idea. However, when used with an object literal, it can be a very handy way to create private variables. This: [...] […] Normally, the with statement is a pretty bad idea. However, when used with an object literal, it can be a very handy way to create private variables. This: […]

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