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From: David Mark on 13 Mar 2010 12:44
Stefan Weiss wrote:
> On 10/03/10 17:35, Lasse Reichstein Nielsen wrote:
>> SAM <stephanemoriaux.NoAdmin(a)wanadoo.fr.invalid> writes:
>>> My Firefox tells me 'undefined' for all that alerts :
>>>
>>> var b = [1,2,,4,5];
>>> alert(b[2]);
>> Yes, reading a non-existing property yields the undefined value.
>> This is no different from doing:
>> var x = new Object();
>> alert(x.arglebargle);
>> The object x has the property "arglebargle", so trying to read
>> it yields undefined.
>
> Aside, because it just came up on the JSLint mailing list: when strict
> warnings are enabled in Firefox, trying to access x.arglebarle will
> trigger a warning, but accessing a nonexistent array index will not. I'm
> not sure if that's very logical or consistent.
>

That's one of the things I don't like about FF strict mode.

if (myObject.myProperty) {
// Not there, so what? Perhaps create it.
}

What do they want you to do? Use typeof?

I haven't used that thing in ages. Is there a way to filter such
spurious warnings so you can see real problems? If not, it's useless in
my book.
From: "Michael Haufe ("TNO")" on 13 Mar 2010 17:53
On Mar 13, 11:44 am, David Mark <dmark.cins...(a)gmail.com> wrote:

> That's one of the things I don't like about FF strict mode.
>
> if (myObject.myProperty) {
>   // Not there, so what?  Perhaps create it.
>
> }
>
> What do they want you to do?  Use typeof?
>
> I haven't used that thing in ages.  Is there a way to filter such
> spurious warnings so you can see real problems?  If not, it's useless in
> my book.

A warning won't be thrown if you're referencing an undefined property
in an if. The warning will be thrown if its used in other places,
which I think is understandable:

var x = {};
if(x.arglebargle){
//no warning is thrown
}
////////////////////////
var x = {};
alert(x.arglebargle); //warning thrown
////////////////////////
var x = {};
function foo(x){}
foo(x.arglebargle); //warning thrown


I don't see where the complaint would be.
From: "Michael Haufe ("TNO")" on 13 Mar 2010 17:55
On Mar 13, 4:53 pm, "Michael Haufe (\"TNO\")"
<t...(a)thenewobjective.com> wrote:

> A warning won't be thrown if you're referencing an undefined property
> in an if. The warning will be thrown if its used in other places,

s/in an if/in an if statement
From: David Mark on 13 Mar 2010 18:15
Michael Haufe ("TNO") wrote:
> On Mar 13, 11:44 am, David Mark <dmark.cins...(a)gmail.com> wrote:
>
>> That's one of the things I don't like about FF strict mode.
>>
>> if (myObject.myProperty) {
>> // Not there, so what? Perhaps create it.
>>
>> }
>>
>> What do they want you to do? Use typeof?
>>
>> I haven't used that thing in ages. Is there a way to filter such
>> spurious warnings so you can see real problems? If not, it's useless in
>> my book.
>
> A warning won't be thrown if you're referencing an undefined property
> in an if. The warning will be thrown if its used in other places,
> which I think is understandable:
>
> var x = {};
> if(x.arglebargle){
> //no warning is thrown
> }
> ////////////////////////
> var x = {};
> alert(x.arglebargle); //warning thrown
> ////////////////////////
> var x = {};
> function foo(x){}
> foo(x.arglebargle); //warning thrown
>
>
> I don't see where the complaint would be.

Probably in my faulty memory. As mentioned, I haven't used the thing in
ages. I know there was something it did that I didn't like though.
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