Question

The jQuery documentation states that

As of jQuery 1.6, the .attr() method returns undefined for attributes that have not been set.

However, I have a case where I’d like a method to return undefined if I go looking for an attribute that is not defined, but an empty string for attributes that have been set to have no value.

Given the following markup:

<p data-withvalue="hello there!" data-novalue="">

I’d like javascript that works like this:

$('p').attr('data-withvalue') => "hello there!"
$('p').attr('data-novalue') => ""
$('p').attr('data-notthere') => undefined

Downgrading jQuery is not an option. Is this possible?

(Note: looking at “inspect element” in the Chrome developer tools, I note that data-novalue="" has been changed to data-novalue. I don’t know if all browsers interpret it like that, but I need this to be cross-browser compatible…)

Answer 1

Unless I’m mistaken, that’s exactly how it’s working with jQuery 1.6.2

Demo: http://jsfiddle.net/xJfpX/

Output:

hello there!

undefined