jQuery has changed the way we write Javascript by abstracting out much of the painful cross-browser implementation details that used to plague developers, but to use it correctly still requires a little knowledge about what’s going on under the hood. In this post we’ll take a good look at jQuery’s selectors and how to use them efficiently.
Wealthfront Engineering: jQuery the Right Way.
One of the best explanations of how jQuery works and how to use it properly I’ve seen. Best part is the inclusion of things that will actually slow jQuery down, resulting in a poor experience for your visitors, coupled with faster alternatives.