arrow-functions

I'm trying to use arrow functions in node v0.10.33 under Ubuntu 14.04 (I'm running node with --harmony flag), but I'm getting this error: console.log( [1,2,3,4].map(x => x*x) ); ^ SyntaxError: Unexpected token > at Module._compile (module.js:439:25) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12) at Function.Module.runMain (module.js:497:10) at startup (node.js:119:16) at node.js:906:3 This should work now in node v0.12.x, with the --harmony flag. Also note that you can get arrow functions in node using the babel

I've converted some classes from the conventional form: class TestOverloads { private status = "blah"; public doStuff(selector: JQuery); public doStuff(selector: string); public doStuff(selector: any) { alert(this.status); } } to use arrow function expressions instead: class TestOverloads2 { private status = "blah"; public doStuff = (selector: any) => { alert(this.status); } } so as to avoid scoping problems when the class methods are used in a callback (see here for background). I can't work out how to recreate my overloaded function signatures though. How would I write my overloads when

I want to transform this code: var formatQuoteAmount = function (tx) { return Currency.toSmallestSubunit(tx.usd, 'USD'); }; var quoteAmounts = res.transactions.map(formatQuoteAmount); into an anonymous arrow function. I've written this: var quoteAmounts = res.transactions.map(tx => Currency.toSmallestSubunit(tx.usd, 'USD')); I get expression expected syntax error at the arrow. I looked up the default syntax here and seems like the syntax of my code is correct. Any ideas what the problem might be? I have it working with this syntax: var quoteAmounts = res.transactions.map(function (tx) { return

This question already has an answer here: Are 'Arrow Functions' and 'Functions' equivalent / exchangeable? 1 answer I am curious about ES6 arrow functions (fat arrow functions). Are they simply syntactic sugar derived from CoffeeScript, or is there more to them than meets the eye? ES6 Arrow functions in depth One of the prettiest features of ES6, it could easily win a beauty contest, if such a contest would be held. What many people don’t know is that the arrow function is not simply a form of syntactic sugar that we can use instead of the regular callback. As I like to explain it to the

I am able to use this.variable to access variables in any part of the component, except inside RxJS functions like subscribe() or catch() . In the example below, I want to print a message after running a process: import {Component, View} from 'angular2/core'; @Component({ selector: 'navigator' }) @View({ template: './app.component.html', styles: ['./app.component.css'] }) export class AppComponent { message: string; constructor() { this.message = 'success'; } doSomething() { runTheProcess() .subscribe(function(location) { console.log(this.message); }); } } When I run doSomething() , I get

Here's a normal ES5 function in my Angular code which works: app.run(function($templateCache){ $templateCache.put('/some','thing') }); I wanted to convert it to ES6 arrow function app.run($templateCache => $templateCache.put('/some','thing')); but it gives the error Uncaught Error: [$injector:unpr] Unknown provider: '/some'Provider <- '/some' http://errors.angularjs.org/1.4.6/$injector/unpr?p0='%2Fsome'Provider%20%3C-%20'%2Fsome' REGEX_STRING_REGEXP @ angular.js:68 (anonymous function) @ angular.js:4287 getService @ angular.js:4435 (anonymous function) @ angular.js:4292 getService @ angular.js

This question already has an answer here: When should I use Arrow functions in ECMAScript 6? 9 answers As far as I know, arrow function is similar to normal function. There is no problem when I use like this: let X = () => {}; let Y = function() {}; X(); Y(); However, error occurred when I use them with new let X = () => {}; let Y = function() {}; x = new X(); y = new Y(); Uncaught TypeError: X is not a constructor Would you please explain me why? Many thanks. You may wish to clarify your question. Q. What did I do wrong? A. You used new with an arrow function, and that's not allowed. Q. Can I