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Tag: arrow-functions

What is the lexical environment inside a callback function?

I keep hearing that arrow functions inherit the value of this from their Lexical Environment. Consider this example: Why is the value of this inside the arrow callback functions undefined (or in non-strict mode: window)? If the callback function is using the value of this from its lexical environment, shouldn’t the lexical environment be addEventListener? Answer When you call a

Arrow function without curly braces

I’m new to both ES6 and React and I keep seeing arrow functions. Why is it that some arrow functions use curly braces after the fat arrow and some use parentheses? For example: vs. Answer The parenthesis are returning a single value, the curly braces are executing multiple lines of code. Your example looks confusing because it’s using JSX which

JSDoc: arrow function params

I’m trying to document my code with JSDoc (EcmaScript 2015, WebStorm 12 Build 144.3357.8). I have an arrow function which I want to document its parameters. This two examples work (I get auto-completion): But when I want to document an arrow function in forEach function, for example, the auto-completion isn’t working (all of the below): Has anyone managed to get

Can I use ES6’s arrow function syntax with generators? (arrow notation)

That is, how do I express with arrow syntax? I’ve tried all the combinations I could think of, and I can’t find any documentation on it. (I am currently using Node.js v0.11.14.) Answer 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