ecmascript-6

问题 I'm building a react application, and I'm importing a node module which uses the spread operator ... and I'm getting an error "Module parse failed: Unexpected token (100:6)" at this operator. How can I get this to work? Thanks 回答1: The create-react-app cli has already bundled this ES2015 feature. Older babel does not support this and needs to be installed separately Now assuming you setup your react manually and not using the create-react-app. You can set up this by installing the package

问题 I'm building a react application, and I'm importing a node module which uses the spread operator ... and I'm getting an error "Module parse failed: Unexpected token (100:6)" at this operator. How can I get this to work? Thanks 回答1: The create-react-app cli has already bundled this ES2015 feature. Older babel does not support this and needs to be installed separately Now assuming you setup your react manually and not using the create-react-app. You can set up this by installing the package

问题 Hi I want pass antwoord to opleidingArray.forEach(haalScoresOp, antwoord); So I can use it in the HaalScoresOp function. I cannot get this to work. I also tried binding but this does not function. I am getting antwoord is not defined as an error. var antwoordenPerVraag = [2,1,3]; console.log(VragenEnScores.vragen[0].opleidingen[0]); antwoordenPerVraag.forEach(berekenEindresultaten); function berekenEindresultaten(item, index) { var opleidingArray = VragenEnScores.vragen[index].opleidingen;

问题 I am trying to sum the unit value by date, and create a new array where there are no duplicate dates. For example, I want to calculate the total of 2015-12-04 00:01:00 . This date has occurred 2 times in the following data, its value is 5 and 6 , which is going to be: [{date: '2015-12-04 00:01:00', unit: 11}, ... etc] I have tried arr = results.map(x => x.unit).reduce((a,c) => a + c) but it only return a single value, not an array. results = [ { unit: 5, date: '2015-12-04 00:01:00' }, { unit:

问题 I am trying to sum the unit value by date, and create a new array where there are no duplicate dates. For example, I want to calculate the total of 2015-12-04 00:01:00 . This date has occurred 2 times in the following data, its value is 5 and 6 , which is going to be: [{date: '2015-12-04 00:01:00', unit: 11}, ... etc] I have tried arr = results.map(x => x.unit).reduce((a,c) => a + c) but it only return a single value, not an array. results = [ { unit: 5, date: '2015-12-04 00:01:00' }, { unit:

问题 This question already has answers here : Curly Brackets in Arrow Functions (2 answers) Closed 9 months ago . I have a .map() function that changes isActive property value of objects in data array. However wraps it with curly braces returns me undefined whereas wrapping it with parenthesis or no wrap returns the updated value. Curly braces are used as a wrapper in an arrow function but does it work differently for .map()? const newData = data.map((data) => { data.label === label ? { ...data,

问题 I am showing data through API ( Data is showing in Pagination ) , API were built in Loopback . I want to sort in my project . For example if User click on Table head attribute then It will sort data in asc and desc . I am new ReactJS don't have much knowledge to implement this logic, Could someone please help me to figure out . Thanks Code class Example extends React.Component { constructor(props) { super(props); this.state = { Item: 5, skip: 0 } this.handleClick = this.handleClick.bind(this)

问题 Example: let tmp; try { tmp = require('module-name'); } catch(e) { return; } I get error (react native Metro Bundler): error: bundling failed: Error: Unable to resolve module `module-name` from ... How to require "module-name" only if exist? 回答1: That's what works for me: let myPackage; const myPackageToRequire = 'my-package-to-require'; try { myPackage = require.call(null, myPackageToRequire); } catch (e) {} The variable definition const myPackageToRequire = 'my-package-to-require'; is

问题 I'm new to JS and trying to use map array.prototype.map() function in my code. I need to add one property to the array's each element without changing the main object structure. I have this array of objects const nav = [ { name: 'Home', title: 'Dashboard', icon: 'home', }, { name: 'About', icon: 'layout-auto', title: 'About', }, { name: 'Applications', icon: 'applications', title: 'Applications', }, ]; after mapping through this array it also chaging main nav array's objects. const mappedNav

问题 I want to access the value of state/property in new state prop. Actually I have already state property where I am storing value of Item=5 and I create UrlParam Where I am storing URL but I need Item numeric value in URL property. I am new to React , Somebody please help me how to do this ? When I getting Error TypeError: Cannot read property 'Item' of undefined , Could someone please help me ? Code this.state={ Item : 5, skip:0, urlParams:`http://localhost:8001/meetups?filter[limit]=${(this