You’ve hit the nail on the head, because of block scoping you can’t declare a const in a try catch block and use it outside the block. You have 2 3 options: Use let: let foo; try{ foo = bar[global.name].foofoo[global.name2]; }catch (err){ console.log(error(err.message)); } Or if there is very little code to come after the … Read more
Object.keys() iterates only enumerable properties of the object. And ES6 methods are not. You could use something like getOwnPropertyNames(). Also methods are defined on prototype of your object so you’d need Object.getPrototypeOf() to get them. Working example: for (let name of Object.getOwnPropertyNames(Object.getPrototypeOf(callbacks))) { let method = callbacks[name]; // Supposedly you’d like to skip constructor if … Read more
I’ve been researching in the past 3 weeks and turns out many people are thinking about an alternative after Angular took a drastic change path. Fortunately the upcomming W3C Web Components standard actually has all we need and it works right now with polyfills from the Polymer project. So to answer the question: Angular Directives … Read more
In Browsers First of all no – there is no built in for this. Lots of libraries that enhance ES2015 promises like bluebird whip with it. I think the other answer conflates executing the function and a delay, it also creates timeouts that are impossible to cancel. I’d write it simply as: function delay(ms){ var … Read more
The same thing happened to me, the solution was the one mentioned by the user span -> Passing arrow function instead of regular function in the callback. Arrow functions don’t have its own this. Difference between regular functions and arrow functions here
You use its size property. Both Maps and Sets have it (here and here). const populatedSet = new Set([‘foo’]); console.log(populatedSet.size); // 1 const populatedMap = new Map([[‘foo’, 1]]); console.log(populatedMap.size); // 1 (Side note: WeakMaps and WeakSets don’t have size or several other features their “strong” counterparts have, in order to keep their implementations, and code … Read more
filter is a method on arrays. Since the code you posted contains an object, you’re seeing this error. You may want to apply filter after getting all the values from the object using Object.values, like this: var users = { “1”: { “user_id”: 1, “test”: “”, “user_name”: “potato0”, “isok”: “true” }, “2”: { “user_id”: 2, … Read more
Inside of your anonymous function this is the global object. Inside of test, this is the instance of MyObject on which the method was invoked. Whenever you call a function like this: someFunction(); // called function invocation this is always the global object, or undefined in strict mode (unless someFunction was created with bind** — … Read more
If you’re going to use ES6, why not use all of ES6, i.e. default values for parameters and destructuring assignment class myClass { constructor({a=”default a value”, b = ‘default b value’, c=”default c value”} = {a:’default option a’, b:’default option b’, c:’default option c’}) { this.a = a; this.b = b; this.c = c; } … Read more
To me, this seems to be one of the biggest unaddressed issues of the JS community. There are no best practices around dependency management and dependency injection around (at least to my knowledge). There is a long discussion on this thread: Do I need dependency injection in NodeJS, or how to deal with …?, but … Read more