It’s a named export vs a default export. export const is a named export that exports a const declaration or declarations. To emphasize: what matters here is the export keyword as const is used to declare a const declaration or declarations. export may also be applied to other declarations such as class or function declarations. … Read more
In TypeScript or using Babel, you can import json file in your code. // Babel import * as data from ‘./example.json’; const word = data.name; console.log(word); // output ‘testing’ Reference: https://hackernoon.com/import-json-into-typescript-8d465beded79
There’s no problem with what you’ve done, but you must remember the difference between function declarations and function expressions. A function declaration, that is: function doSomething () {} Is hoisted entirely to the top of the scope (and like let and const they are block scoped as well). This means that the following will work: … Read more
@thefourtheye is correct in saying that these variables cannot be accessed before they are declared. However, it’s a bit more complicated than that. Are variables declared with let or const not hoisted? What is really going on here? All declarations (var, let, const, function, function*, class) are “hoisted” in JavaScript. This means that if a … Read more
I don’t think this is possible, but afaik the resolution of module names is up to module loaders so there might a loader implementation that does support this. Until then, you could use an intermediate “module file” at lib/things/index.js that just contains export * from ‘ThingA’; export * from ‘ThingB’; export * from ‘ThingC’; and … Read more
Can I use ES6’s arrow function syntax with generators? You can’t. Sorry. According to MDN The function* statement (function keyword followed by an asterisk) defines a generator function. From a spec document (my emphasis): The function syntax is extended to add an optional * token: FunctionDeclaration: “function” “*”? Identifier “(” FormalParameterList? “)” “{” FunctionBody “}”
If you want to find webpack files and configurations go to your package.json file and look for scripts You will find that scripts object is using a library react-scripts Now go to node_modules and look for react-scripts folder react-script-in-node-modules This react-scripts/scripts and react-scripts/config folder contains all the webpack configurations.
New Answer: Much of the below was true, until the introduction of React Hooks. componentDidUpdate can be replicated with useEffect(fn), where fn is the function to run upon rerendering. componentDidMount methods can be replicated with useEffect(fn, []), where fn is the function to run upon rerendering, and [] is an array of objects for which … Read more
Let is a mathematical statement that was adopted by early programming languages like Scheme and Basic. Variables are considered low level entities not suitable for higher levels of abstraction, thus the desire of many language designers to introduce similar but more powerful concepts like in Clojure, F#, Scala, where let might mean a value, or … Read more
Use Array.prototype.keys: for (const index of [1, 2, 3, 4, 5].keys()) { console.log(index); } If you want to access both the key and the value, you can use Array.prototype.entries() with destructuring: for (const [index, value] of [1, 2, 3, 4, 5].entries()) { console.log(index, value); }