You can export like this: import App from ‘./App’; import Home from ‘./Home’; import PageWrapper from ‘./PageWrapper’; export { App, Home, PageWrapper } Then, you can import like this wherever you need it: import { App, PageWrapper } from ‘./index’ //or similar filename … You can read more about import and export here. I also … Read more
In ES6, derived classes have to call super() if they have a constructor. In react, all components extend from the Component class. You don’t actually need a constructor for every ES6/react class. If no custom constructor is defined, it will use the default constructor. For base classes, it is: constructor() {} And for derived classes, … Read more
Since it’s a stateless component it doesn’t have the component lifecycle. Therefor you can’t specify a constructor. You have to extend React.Component to create a stateful component which then will need a constructor and you’ll be able to use the state. Update Since React 16.8.0 and Hooks got introduced there are more options. Hooks are … Read more
You can achieve it with a form of destructuring: const user = { _id: 1234, firstName: ‘John’, lastName: ‘Smith’ }; const { _id, …newUser } = user; console.debug(newUser); Browser support: The spread (…) syntax was introduced with ES2018, and most browsers even supported it before ES2018 was finalized. So as of 2023, you can rely … Read more
You probably confused by the difference between null and undefined, For example: const { dogName=”snickers” } = { dogName: undefined } console.log(dogName) // what will it be? ‘snickers’! const { dogName=”snickers” } = { dogName: null } console.log(dogName) // what will it be? null! const { dogName=”snickers” } = { dogName: false } console.log(dogName) // … Read more
No, it’s not possible. (Disclaimer: your syntax works and does both destructuring and returning, but it is equivalent to ({ id, name, price } = newItem); // assigns global variables return newItem; which is probably not what you wanted) To do what you want (which I assume is creating a new object), you need to … Read more
There have a simple method. Just assign the object to instance(this) class Model { constructor(obj){ Object.assign(this, obj) } print(){ console.log(this.a); } } let obj = {a: ‘a’, b: ‘b’, c: ‘c’} let m = new Model(obj) console.log(m) m.print() // ‘a’
An alternative to this would be to use css to display it with line breaks. This also makes it easier to copy and paste with the original line breaks as well as distinguishing between one break (\n) and two breaks (\n\n). Just add the style white-space: pre-wrap; to your element. <div style={{whiteSpace: “pre-wrap”}}>{note.note}</div> There are … Read more
The problem was not with the recursion. Your function did call itself recursively, it just didn’t yield values outside. When you call helper(), you get an iterator as a return value, but you wanted the iterated values of that iterator to be yielded. If you want to yield recursively, you need to yield *. Try … Read more
Understand that ES2015 Map keys are compared (almost) as if with the === operator. Two array instances, even if they contain the same values, do not ever compare as === to each other. Try this: var a = new Map(), key = [‘x’, ‘y’]; a.set(key, 1); console.log(a.get(key)); Since the Map class is intended to be … Read more