jQuery $.data() conditional statement

I'm using the html5 "data" attribute on a element, and I want to assign the attribute value to a variable only if it exists and if it's not empty:

var xx开发者_运维知识库x = $(this).data('what') ? $(this).data('what') : 'default_value';

but it doesn't work. I always get the default value...

Using a short circuit is simpler and more efficient:

var xxx = $(this).data('what') || 'default_value';

But your code should have worked anyway, assuming the data existed (as the commenter noted).

Looks like $(this) is not what you expect it to be. Other than that, the statement looks fine. Demo

According to the documentation:

.data()

The .data() method allows us to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks.

.attr()

The .attr() method gets the attribute value for only the first element in the matched set.

So what you want is to use the .attr() method, like this:

var xxx = $(this).attr('data-what') || 'default_value';