No, that’s not the rule I would use. The major use-case I’ve found for the fat-arrow in defining methods is when you want to use a method as a callback and that method references instance fields: class A constructor: (@msg) -> thin: -> alert @msg fat: => alert @msg x = new A(“yo”) x.thin() #alerts … Read more
Why you shouldn’t use inline arrow functions in JSX props Using arrow functions or binding in JSX is a bad practice that hurts performance, because the function is recreated on each render. Whenever a function is created, the previous function is garbage collected. Rerendering many elements might create jank in animations. Using an inline arrow … Read more
This has nothing to do with Traceur and turning something off; this is simply how ES6 works. It’s the specific functionality you’re asking for by using => instead of function () { }. If you want to write ES6, you need to write ES6 all the time. You can’t switch in and out of it … Read more
The reason why this style can be used (and possibly why it was used here) is that _ is one character shorter than (). Optional parentheses fall into the same style issue as optional curly brackets. This is a matter of taste and code style for the most part, but verbosity is favoured here because … Read more
Is it possible to export Arrow functions in ES6/7? Yes. export doesn’t care about the value you want to export. The export statement below gives a syntax error … why? You cannot have a default export and give it a name (“default” is already the name of the export). Either do export default () => … Read more
You need to make it a function expression instead of function definition which doesn’t need a name and makes it a valid JavaScript. (() => { console.log(‘Ok’); })(); Is the equivalent of IIFE (function() { console.log(‘Ok’); })(); And the possible reason why this works in Node.js but not in Chrome, is because its parser interprets … Read more
Jackson has partially answered this in a similar question: Implicit return, but only if there is no block. This will result in errors when a one-liner expands to multiple lines and the programmer forgets to add a return. Implicit return is syntactically ambiguous. (name) => {id: name}returns the object {id: name}… right? Wrong. It returns … Read more
Your syntax is slightly off, just missing an equals sign after the property name. class SomeClass extends React.Component { handleInputChange = (val) => { console.log(‘selectionMade: ‘, val); } } This is an experimental feature. You will need to enable experimental features in Babel to get this to compile. Here is a demo with experimental enabled. … Read more
How do I write a named arrow function in ES2015? You do it the way you ruled out in your question: You put it on the right-hand side of an assignment or property initializer where the variable or property name can reasonably be used as a name by the JavaScript engine. There’s no other way … Read more
Can I use ES6’s arrow function syntax with generators? You can’t. Sorry. According to MDN The function* statement (function keyword followed by an asterisk) defines a generator function. From a spec document (my emphasis): The function syntax is extended to add an optional * token: FunctionDeclaration: “function” “*”? Identifier “(” FormalParameterList? “)” “{” FunctionBody “}”