jQuery Forum

var x = window.x = "hello";

What I mean is: If you set x via something like :
var x = 10;
then 'magically'
window.x is 10

A combination of the language spec and the implementation. Global
variables are properties of an implicit global object. Name depends on
interpreter: window, global, etc.

> What I mean is: If you set x via something like :
> var x = 10;
> then 'magically'
> window.x is 10
>
function() {
var x = 10; // local scope
y = 20; // no 'var' keyword used hence global scope
}
alert(window.x); // undefined
alert(window.y); // 20
-- Aleem

> function() {
> var x = 10; // local scope
> y = 20; // no 'var' keyword used hence global scope}
>
> alert(window.x); // undefined
> alert(window.y); // 20
Yes - but if you do outside the function scope it does get set.
I guess it's a bit like the 'with' operator ?

> I guess it's a bit like the 'with' operator ?
avoid 'with'
http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/
and more specifically, crockford's nail in the coffin
http://yuiblog.com/blog/2006/04/11/with-statement-considered-harmful/#comment-720

I honestly consider the outright statements against with to be
overboard. I've been using the with statement quite reliably inside my
code at work. I think the issue is misuse of with. One shouldn't go
using with in the intent to do `with(foo) {bar = 'baz';}` and have
foo.bar modified. In fact I don't believe with should be used with any
intent to set at all (except for the case where Bar exists in foo, and
you want to set .someprop on Bar, that is a different case). With is
quite effective in use for importing things like libraries into local scope.
ns.my.lib; Defines camelCaseMe, and runMe; You can use `with(ns.my.lib)`
with the intent to allow you to use camelCaseMe and runMe in the local
scope.
~Daniel Friesen (Dantman, Nadir-Seen-Fire) [http://nadir-seen-fire.com]
-Nadir-Point & Wiki-Tools (http://nadir-point.com) (http://wiki-tools.com)
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-Soul Eater Wiki (http://souleater.wikia.com)
Aleem B

On Mon, Feb 23, 2009 at 4:24 PM, Daniel Friesen
<nadir.seen.fire@gmail.com>

>> It's the reason why developers ought to use ("mystring"==myvar) instead of (myvar=="mystring").
For what reason is this ?

>>> It's the reason why developers ought to use ("mystring"==myvar) instead of (myvar=="mystring").
> For what reason is this ?
It mitigates the following class of bugs (not the single = sign instead of ==):
if (myvar = "mystring") // will compile/run but behave incorrectly
if ("mystring" = myvar) // won't compile/run and you can fix it right away
Based on an earlier response in the thread, if this seems pedantic to
some readers, take into consideration that millions of programmers
will be writing billions of if statements each year which will yield a
thousand bugs at an error rate of 0.0001% or 1 in a million. The
cost-benefit of simply switching the order is clear.
-- Aleem