destructuring

问题 In es6, how can i simplify the following lines using destructuring?: const array0 = someArray[0].data; const array1 = someArray[1].data; const array2 = someArray[2].data; 回答1: Whether using destructuring would actually be a simplification is debatable but this is how it can be done: const [ { data: array0 }, { data: array1 }, { data: array2 } ] = someArray Live Example: const someArray = [ { data: 1 }, { data: 2 }, { data: 3 } ]; const [ { data: array0 }, { data: array1 }, { data: array2 } ]

问题 In es6, how can i simplify the following lines using destructuring?: const array0 = someArray[0].data; const array1 = someArray[1].data; const array2 = someArray[2].data; 回答1: Whether using destructuring would actually be a simplification is debatable but this is how it can be done: const [ { data: array0 }, { data: array1 }, { data: array2 } ] = someArray Live Example: const someArray = [ { data: 1 }, { data: 2 }, { data: 3 } ]; const [ { data: array0 }, { data: array1 }, { data: array2 } ]

问题 In es6, how can i simplify the following lines using destructuring?: const array0 = someArray[0].data; const array1 = someArray[1].data; const array2 = someArray[2].data; 回答1: Whether using destructuring would actually be a simplification is debatable but this is how it can be done: const [ { data: array0 }, { data: array1 }, { data: array2 } ] = someArray Live Example: const someArray = [ { data: 1 }, { data: 2 }, { data: 3 } ]; const [ { data: array0 }, { data: array1 }, { data: array2 } ]

问题 This question already has answers here : What are the rules for JavaScript's automatic semicolon insertion (ASI)? (6 answers) Closed 1 year ago . I've just noticed a strange error when using Javascript destructuring assignment, which took me some guesswork to resolve. I'm posting here so I can show what I learned. (I accept that the question about Javascript semicolon insertion is answered by What are the rules for JavaScript's automatic semicolon insertion (ASI)?, but my problem was about

问题 This question already has answers here : What are the rules for JavaScript's automatic semicolon insertion (ASI)? (6 answers) Closed 1 year ago . I've just noticed a strange error when using Javascript destructuring assignment, which took me some guesswork to resolve. I'm posting here so I can show what I learned. (I accept that the question about Javascript semicolon insertion is answered by What are the rules for JavaScript's automatic semicolon insertion (ASI)?, but my problem was about

问题 I am trying to destructure an array of objects with three properties into three separate arrays for example maybe something like const {wlAddresses,wlTokens,wlTickets} = Object.map() or const [wlAddresses,wlTokens,wlTickets] = Object.map() Where Object.map() returns something like this [{ wlAddresses: '23', wlTokens: 1, wlTickets: 3 }, { wlAddresses: '24', wlTokens: 1, wlTickets: 2 }, { wlAddresses: '25', wlTokens: 1, wlTickets: 3 }] I tried with that method and it only returns the first

问题 I don’t understand the parameter of const Posts below. I’m fairly new to node/React. Is it a destructured parameter object? Or is it just an object being passed as a parameter? getPosts and post are showing as undefined. But I don’t understand where the parameter object is being passed from into the function... Full code here: https://github.com/bradtraversy/devconnector_2.0/blob/master/client/src/components/posts/Posts.js Thanks in advance!! import React, { Fragment, useEffect } from 'react'

问题 I have a component that receives a prop that looks like this: const styles = { font: { size: { value: '22', unit: 'px' }, weight: 'bold', color: '#663300', family: 'arial', align: 'center' } }; I'm trying to update the align property, but when I try to update the object, I wind up replacing the whole object with just the align property. this is how I'm updating it: const { ...styling } = styles; const [style, setStyle] = useState(styling); return ( <RadioButtonGroup onChange={(event) => {

问题 Is it possible to use destructuring assignment in a JavaScript class' constructor to assign the instance variables similar to how you can do it to normal variables? The following example works: var options = {one: 1, two: 2}; var {one, two} = options; console.log(one) //=> 1 console.log(two) //=> 2 But I cannot get something like the following to work: class Foo { constructor(options) { {this.one, this.two} = options; // This doesn't parse correctly and wrapping in parentheses doesn't help }

问题 If i want to destruct an Object i would do : const obj = { a: 'a', fn: () => 'some function' } // const fn = obj.fn; // OR const { a, fn } = obj; console.log( fn() ); this doesn't work for the Date Object : Uncaught TypeError: this is not a Date object. const date = new Date(); const day = date.getDate(); console.log(day); // works const { getDate } = date; console.log( getDate() ); // doesn't work Why is this possible with the first Object and not with the Date ? how would one acheive that