Javascript是什么更快？ IF语句中的多个OR以目标CSS为目标，或者一个IF具有多个CSS目标

Question

I have set some code to function if the current page contains one of the following attributes below

if($('body[data-section="chicken"]').length || $('body[data-section="friedchicken"]').length){ 
    (function() {
      ///...
    }
}

Now i could simply do it like:

if($('body[data-section="chicken"],body[data-section="friedchicken"]').length){ 
    (function() {
      ///...
    }
}

Basically, a function to auto scroll down on the targeted pages. But i'm curious! which one is faster to detect these targets? and the reason I'm asking because i will be using more than 2 css selectors.

Answer 1

If speed is a concern, then skip the jQuery layer, address the body element directly, and only query for its data-section attribute once:

var attr = document.body.getAttribute('data-section');
if (attr == 'chicken' || attr == 'friedchicken') {
    // ...
};