987889 - Initialiser expression in the for(in) statement on bf4 site

Status: RESOLVED FIXED

(Web Compatibility :: Site Reports, defect)

Description

[Mike Taylor [:miketaylr]]

From es-discuss:

On 3/14/14, 15:53, Brendan Eich wrote:> Andreas Rossberg wrote:
>> On 14 March 2014 00:59, Oliver Hunt<[e-mail]>  wrote:
>>> >  JSC has been trying to kill off the initialiser expression in the for(in)
>>> >  statement, but we've encountered a bunch of reasonably significant content
>>> >  that breaks with it disallowed (a particularly prominent one currently is
>>> >  http://battlelog.battlefield.com/bf4/), so we will be bringing back support
>>> >  for
>>> >
>>> >  for (var Identifier = Expression in Expression)
>>
>> I'd be curious to know what the actual code is, and to get an idea why
>> they are using it that way.
> 
> http://battlelog.battlefield.com/bf4/
>     for (var i = 0 in debug.audio)
> 
> I say we should evangelize this site. Cc'ing some awesome Mozilla site
> evangelists.

Comment 1

[Mike Taylor [:miketaylr]]

http://eaassets-a.akamaihd.net/bl-cdn/cdnprefix/B3e85add4d509011e5347bc29966cba2fa6ced6ae/public/generated/en_US/bundle_base_bottombundles_2189137393.js

for(var i=0 in debug.audio){var elem=debug.audio[audioLength-i-1];

Comment 2

[Mike Taylor [:miketaylr]]

Adam, do you think you could help us find a contact here?

Comment 3

[Mike Taylor [:miketaylr]]

So the suggested fix is simple here, just use a regular for loop:

for (var i = 0; i < audioLength; i++) {
    var elem = debug.audio[audioLength-i-1];
    ...
}

Comment 4

[Mike Taylor [:miketaylr]]

So it turns out an irc buddy (Markus) can likely help us out on this. CCing him. (small world and all that)

Comment 5

[Marcus Ekwall]

Ugh, that's some ugly code! Fix committed :)

Comment 6

[Mike Taylor [:miketaylr]]

Thanks so much!

Comment 7

[Mike Taylor [:miketaylr]]

Code is no longer on the site. Thanks again Marcus.