Node.js is just JavaScript running on the server side. That's it. That's all there is to it.
- Express Docs, if you want to get started and already know JavaScript this is the place to be
Node.js is just JavaScript running on the server side. That's it. That's all there is to it.
// === Arrays | |
var [a, b] = [1, 2]; | |
console.log(a, b); | |
//=> 1 2 | |
// Use from functions, only select from pattern | |
var foo = () => [1, 2, 3]; |
// array utils | |
// ================================================================================================= | |
const combine = (...arrays) => [].concat(...arrays); | |
const compact = arr => arr.filter(Boolean); | |
const contains = (() => Array.prototype.includes | |
? (arr, value) => arr.includes(value) | |
: (arr, value) => arr.some(el => el === value) |
All libraries have subtle rules that you have to follow for them to work well. Often these are implied and undocumented rules that you have to learn as you go. This is an attempt to document the rules of React renders. Ideally a type system could enforce it.
A number of methods in React are assumed to be "pure".
On classes that's the constructor, getDerivedStateFromProps, shouldComponentUpdate and render.