Correct data-last-value="43" vs .data( "lastValue" ) === 43; discrepancy

[robertmaxrees]

In the documentation for .data(), there is an example div:

The accompanying example contains this:

All of the following jQuery code will work.
...
2 $( "div" ).data( "lastValue" ) === 43;

The example should be corrected to be more accurate.

[dmethvin]

When referencing data attribute values via .data() you should always use the camelCase rendering. It's documented here: http://www.learningjquery.com/2011/09/using-jquerys-data-apis/

At the time this was implemented there weren't too many embedded dashes so it wasn't an issue. I think the action item here is to explain camelCase.

[robertmaxrees]

That makes much more sense - to be honest I filed this after somebody came into #jquery on freenode complaining about the discrepancy, so I probably should have done a more thorough investigation into it before reporting it.

Clarifying the documentation makes a lot of sense here to me. Good call.

[dmethvin]

Oh I just realized that this was about "43" vs 43, which is already pretty clearly explained in the docs. We try to convert numberish-looking strings to numbers as long as it doesn't change the string representation. So "4E2" doesn't get converted to 400 for example.

[robertmaxrees]

The issue, as was originally presented to the channel, was that it isn't clear that this:
$( "div" ).data( "lastValue")
is a valid reference to the "data-last-value" attribute in the following HTML:

I can't find any place on http://api.jquery.com/data/ that tells you this - instead, it looks like a typo, as there is no explanation that tells you otherwise, unless you go to the "learning jquery" site.

Thanks!

[dmethvin]

Agreed, there is still a docs issue here.