You can import the default export by either import Test2 from ‘./test’; or import {default as Test2} from ‘./test’; The default export doesn’t have Test as a name that you would need to alias – you just need to import the default under the name that you want. The best docs I’ve found so far … Read more
How to Fix a Stale useState Currently, your issue is that you’re reading a value from the past. When you define handleResize it belongs to that render, therefore, when you rerender, nothing happens to the event listener so it still reads the old value from its render. There are a several ways to solve this. … Read more
This is an issue with Javascript source maps, which don’t currently support mapping symbol names, and babel, which changes the names of import-ed modules when compiling to CommonJS from ES2105 module syntax. Babel does this to fully support the fact that ES2015 modules export bindings by resolving all references to imports whenever they are used … Read more
Without the semicolon [1,2,3,4,5,6] will be evaluated as property access. Which is perfectly fine JS, I personally don’t think that adding semicolons is such a big deal so I keep using them.
With using only one reduce() you can do this. you don’t need map(). better approach is this: const values = [1,2,3,4]; const newValues= values.reduce((acc, cur) => { return acc.concat([cur*cur , cur*cur*cur, cur+1]); // or acc.push([cur*cur , cur*cur*cur, cur+1]); return acc; }, []); console.log(‘newValues=”, newValues) EDIT: The better approach is just using a flatMap (as @ori-drori … Read more
Object.keys() returns an array of strings, which are the object’s own enumerable properties. Reflect.ownKeys(obj) returns the equivalent of: Object.getOwnPropertyNames(target). concat(Object.getOwnPropertySymbols(target)) The Object.getOwnPropertyNames() method returns an array of all properties (enumerable or not) found directly upon a given object. The Object.getOwnPropertySymbols() method returns an array of all symbol properties found directly upon a given object. var … Read more
let C = class { // … } Object.defineProperty (C, ‘name’, {value: ‘TheName’}); // test: let itsName = (new C()).constructor.name; // itsName === ‘TheName’ -> true
I believe that defaultProps should do what you need: import PropTypes from ‘prop-types’; class AppButton extends Component { render(){ return ( <button onClick={this.props.onClick}>{this.props.message}</button> ) } }; AppButton.propTypes = { message: PropTypes.string, onClick: PropTypes.func }; AppButton.defaultProps = { message: ‘Hello’, onClick: function(){ alert(“Hello”); } }; From the docs: The defaultProps will be used to ensure that … Read more
EDIT (2021): TC39, which specifies JavaScript still hasn’t resolved exactly how this is supposed to work. That needs to happen before browsers can consistently implement it. You can follow the latest efforts here. Original answer: Instantiating such classes is meant to work; Chrome and Firefox just have bugs. Here’s Chrome’s, here’s Firefox’s. It works fine … Read more
If you are using Vue 3 and dealing with Proxies, Vue provides some methods to help with this: import { isProxy, toRaw } from ‘vue’; Using these, you can check if an object is a proxy with isProxy, for example: isProxy(reactiveObjectOrArray) ? ‘yup’ : ‘nope’ And you can extract the raw data using toRaw: const … Read more