|  | Google Chrome "differences" | | |
| | | Gregor Kofler |  |
|  Posted: Wed Sep 03, 2008 7:10 pm Post subject: Google Chrome "differences" |  |
I've augmented string objects (not the prototype) and none of the
popular browsers ever complained. Until Chrome came along. Chrome won't
accept something like
String.prototype.foo = function() {
if (!this.bar) {
this.bar = [];
}
// this.bar stays always undefined
}
Trying a workaround I came across
String.prototype.bar = [];
String.prototype.foo = function() {
this.bar.push({
o: this,
p: "baz"
});
return this;
}
var x = "foo";
var y = "foo";
x.foo();
y.foo();
alert("".bar[0].o === "".bar[1].o);
yields false in "all" browsers. Chrome returns true.
Any comments on that?
Gregor
--
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LINK ::: meine JS-Spielwiese
LINK ::: Bildagentur für den alpinen Raum |
| |
| | | Lasse Reichstein Nielsen | |
| | Posted: Thu Sep 04, 2008 2:48 pm Post subject: Re: Google Chrome "differences" | |
Gregor Kofler <usenet@gregorkofler.at> writes:
| Quote: | I've augmented string objects (not the prototype) and none of the
popular browsers ever complained. Until Chrome came along. Chrome
won't accept something like
String.prototype.foo = function() {
if (!this.bar) {
this.bar = [];
}
// this.bar stays always undefined
}
.... and ... |
| Quote: | yields false in "all" browsers. Chrome returns true.
Any comments on that?
|
Well spotted.
It's not standard-compliant.
It's a lousy standard at that point - requireing the creation of a new
object every time you access a property of a basic string value
.... like the *length*! - but still, it is the spec.
/L
--
Lasse Reichstein Nielsen
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.' |
| |
| | | Lasse Reichstein Nielsen | |
| | Posted: Thu Sep 04, 2008 3:11 pm Post subject: Re: Google Chrome "differences" | |
Gregor Kofler <usenet@gregorkofler.at> writes:
| Quote: | I've augmented string objects (not the prototype) and none of the
popular browsers ever complained. Until Chrome came along. Chrome
won't accept something like
String.prototype.foo = function() {
if (!this.bar) {
this.bar = [];
}
// this.bar stays always undefined
|
A little testing shows the core problem:
---
String.prototype.foo = function() {
return typeof this;
}
alert("x".foo()); // alerts "string"
---
I.e., some optimization that prevents creating new objects, that
probably works well for built-in functions, is also applied to
user-added methods on String.prototype.
Same problem exists for Number and Boolean.
/L
--
Lasse Reichstein Nielsen
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.' |
| |
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