1. Use Minified JavaScript: Minified JavaScript files are smaller and load faster, resulting in improved performance.
1. Avoid Using Global Variables: Lookups are faster in local scope than in global scope, so keeping variables confined to local scope can improve performance.
1. Use Object & Array Literals: Instead of using new Object() and new Array(), use {} and [] respectively. This is not only shorter, but also faster and easier to read.
1. Limit DOM Access: Accessing the DOM is slow, so limiting your interaction with the DOM can speed up JavaScript performance. For example, store DOM references in variables when elements need to be accessed repeatedly.
1. Use Event Delegation: Instead of attaching event handlers to individual elements, attach a single event handler to a parent element.
1. Limit the Use of Closures: Closures can use up a lot of memory, which can slow down JavaScript performance. Therefore, use them sparingly.
1. Use ‘===’ Instead of ‘==’: The ‘===’ operator checks type and equality, without performing the type conversion that ‘==’ does. This makes ‘===’ faster.
1. Lazy Load: Load scripts and resources only when they are needed. For instance, if certain JavaScript is only needed for user interactions, defer loading until then.
1. Use Web Workers: Taking long-running JavaScript operations off the main thread and running them in the background can improve UI responsiveness.
1. Cache as much as possible: Use memoization techniques in order to facilitate and utilize caching, which could significantly improve your application’s performance.
1. Use tools to identify bottlenecks: Chrome’s DevTools, Firefox’s DevTools offer various profiling and timeline tools to identify slow code paths.
1. Utilize requestAnimationFrame for Animations: This is particularly beneficial for animations as it allows the browser to optimize rendering, improving performance and battery life.
