One of the slowest things you can do with JavaScript is work with the DOM. And one of the slowest DOM operations is performing a query to find DOM elements. Caching those queries can have significant performance impacts. Here’s how you do it. Read more

Understanding global variables and scope is very important in JavaScript. Misunderstanding what a variable’s scope is can lead odd bugs and broken code. This is made more problematic because the default scope in JavaScript is global. But what is global and how should you use it? Read more