ecmascript-next

Using ES6+ syntax in React/React-Native, the variable foo , when defined outside of the constructor is somehow transformed into an instance variable when called with this. . Is my assertion true? Why does it even work, when not instantiated in the constructor? Here a corresponding React Native code snippet: class myComponent extends Component { constructor() { super(); } foo = "bar"; render() { return ( <View>{ this.foo }</View> ); } } This discussion about ES7 property initializers shows how the state variable is prominently used in this way in React/React Native. So far related Stack

I'm getting used to the proposed async/await syntax and there's some unintuitive behavior. Inside the "async" function, I can console.log the correct string. However, when I try to return that string, instead, it returns a promise. Checking this entry: async/await implicitly returns promise? , it's pretty clear that any "async function()" will return a promise, NOT a value. That's fine. But how do you get access to the value? If the only answer is "a callback", that's fine - but I was hoping there might be something more elegant. // src // ========================================== require(

When trying to use async/await in react-native, I am getting the following error: uncaught error Error: SyntaxError: /Users/senthilsivanath/Documents/MusicTulip/index.ios.js: Unexpected token (50:23) 48 | renderScene: function(route,nav) { 49 | try { 50 | const response = await signIn.isLoggedIn(); My .babelrc file is: { "presets": ["react-native", "es2015", "babel-preset-stage-3"] } You might just be missing the async keyword on line 48. Update your code to use the async keyword before the function keyword: renderScene: async function(route, nav) { try { const response = await signIn

I was wondering if there is a way, to destructe and use an array method at the same time? If yes, is it useful to use it, or would it decrease the code readabilty so much, that it's not worth it? My current code is this: const { props: { title, ingredients: ing } } = this; const ingredients = ing.map( (ing, index) => <li key={index}>{ing}</li> ); But I'm trying to find a shorter way like this: const { props: { title, ingredients: ingredients.map( (ing, index) => <li key={index}>{ing}</li> ); } } = this; This code doesn't work though. Any tips would be much appreciated! :) No, this is not

I'm new to nodejs. I’m not seeing the response in ex 1, but i see in ex 2. Why? Await works for me in other places, using babel. Ex 1 let res = await request(url) console.log(res); console.log(res.body); Ex 2 request(url, function (error, res, body) { if (!error && response.statusCode == 200) { console.log(body) } }); Await works in other places, I’m using babel and required modules for es6 and es7 features. For example, await works in squelize call, i validated. But it doesn’t work for request call. Why? You should only await on something that returns a Promise. I would definitely recommend