Development

ES5 and ES6 brought many changes to JavaScript, including better ways of working with arrays. In particular, the `.every()` and `.some()` functions can improve how developers manipulate arrays, and potentially give them performance gains. This article will show that the prominent JavaScript array functions are `.map()`, `.filter()`, and `.reduce()`, and will then go through examples of instances in which `.every()` and `.some()` would be more efficient.

In order to avoid blocking code in JavaScript development, asynchronous coding techniques must be used for operations that take a long time, such as network requests made from Web APIs like Fetch. This article will cover asynchronous programming fundamentals, teaching you about the event loop, the original way of dealing with asynchronous behavior through callbacks, the updated ECMAScript 2015 (ES6) addition of promises, and the modern practice of using async/await.