The each() method supplies two parameters to the callback-function. They are current index and the current item. Thus you could do the following: $(‘ul#mylist > li’).each((i, v) => { $(v).addClass(‘some-class-name’); }); Where the “v” variable is the current “li” element
As you say, => is not an operator. Arrow functions are primary syntax. The rules for them are defined in the specification, starting with the ArrowFunction production. ArrowFunction is defined as ArrowParameters followed by => followed by the misleadingly-named ConciseBody. ConciseBody has two forms. You’re asking about the form using ExpressionBody, which is where the … Read more
No, it’s not allowed in JS either, however there is a proposal to add it. For now, just use the two-step process with importing into a local variable and exporting that: // file: constants.js export const SomeConstant1 = ‘yay’; export const SomeConstant2 = ‘yayayaya’; // file: index.js import * as Constants from ‘./constants.js’; export {Constants};
The export default {…} construction is just a shortcut for something like this: const funcs = { foo() { console.log(‘foo’) }, bar() { console.log(‘bar’) }, baz() { foo(); bar() } } export default funcs It must become obvious now that there are no foo, bar or baz functions in the module’s scope. But there is … Read more
ESLint defaults to ES5 syntax-checking. You’ll want to override to the latest well-supported version of JavaScript. Try adding a .eslintrc.json file to your project. Inside it: { “parserOptions”: { “ecmaVersion”: “latest” }, “env”: { “es6”: true } } Hopefully this helps. EDIT: I also found this example .eslintrc.json which might help.
When you define a and d, the value of this is the top-level window object, since you’re not in the context of some other object, and this gets saved in the arrow functions. window.name is an empty string, so that’s what you see when you call a.func() and d.func(). Arrow functions should generally not be … Read more
Is there a means to define equality for my objects to solve my problem? No not really. There has been some discussion about this on the mailing list. The result is: Build your own Set/Map abstraction on top of Set/Map, which would convert the objects to a primitive value according to your hashing function. Wait … Read more
You can still attach a method on a class‘ prototype; after-all, classes are just syntactic sugar over a “functional object”, which is the old way of using a function to construct objects. Since you want to use ES6, I’ll use an ES6 import. Minimal effort, using the prototype: import getColor from ‘path/to/module’; class Car { … Read more
The language reference uses abstract terms because JavaScript environments can vary widely. In the browser, a window (a frame, a window opened with window.open(), or just a plain browser tab) is a realm. A web worker is a different kind of realm than a window, but it’s a realm. Same goes for service workers. It’s … Read more
TL;DR Indeed ES import statements import default and import * are not the same thing, the fact that they behave the same in this case is a combination of how React authors chose to publish the library and compatibility layers in TypeScript (using esModuleInterop) or Babel and your bundler to make them “just work”. It … Read more