es6-class

问题 In Javascript, with the following illustration code: class Base { constructor() { this._val = 1 } get val() { return this._val } } class Xtnd extends Base { set val(v) { this._val = v } } let x = new Xtnd(); x.val = 5; console.log(x.val); // prints 'undefined' the instance x will not inherit get val()... from Base class. As it is, Javascript treat the absence of a getter, in the presence of the setter, as undefined. I have a situation in which I have many classes that all have the exact same

问题 I think the title is pretty self-descriptive. I've building react components using the class notation, and I noticed that while handleSomething has to be manually bound to this , render and componentWillMount do not. Are method bound to this already? Is it ok to bind manually for notationally consistency's sake? 回答1: Understanding of 'this' in JavaScript The 'this' keyword in a function is determined by the executing scope of the function. For example, the this in someFunction when calling

问题 I have cells (9x9 rows/cols), and I'm trying to create one cell out of the 49 cells to be unique, as you can see when you run the snippet, the cells have random numbers between 20 to 200, and one of these cells have Red color. The problem I'm struggling with, I want that one cell to have Symbol (marking plate) like S or D for example instead of number, How i can achieve that? 回答1: It seems pretty easy as you have a class ( uniqueCell ) in the element. You can simply target the cell with the

问题 I'm having the following TypeScript class export class Vehicule extends TrackableEntity { vehiculeId: number; constructor() { super(); return super.proxify(this); } } my typescript target in tsconfig.json is configured as es6: "compilerOptions": { "module": "es2015", "moduleResolution": "node", "emitDecoratorMetadata": true, "experimentalDecorators": true, "target": "es6", } At runtime, here in Chrome, the code is failing with: ReferenceError: Cannot access 'Vehicule' before initialization at

问题 I was previously rolling my own Javascript OOP but now I'm playing with ES6 and want to use the class defined after definition in a generic way. Note Any answer with new in it is not what I'm after. Pseudo code: // base.js class Base { constructor(arg) { this.arg = arg; } // This is the behaviour I'm after //afterDefined(cls) { afterExtended(cls) { // probably a better name console.log(`Class name ${cls.prototype.name}`); } } // frombase.js class FromBase extends Base { constructor({ p1='val1

问题 New to JavaScript. Seeking some guidance on how to access the calling class name from a static method defined in the superclass using ES6 classes. I've spent an hour searching, but have not been able to come up with a solution. A code snippet may help clarify what I am seeking class SuperClass { get callingInstanceType() { return this.constructor.name } static get callingClassType() { return '....help here ...' } } class SubClass extends SuperClass { } let sc = new SubClass() console.log(sc

问题 New to JavaScript. Seeking some guidance on how to access the calling class name from a static method defined in the superclass using ES6 classes. I've spent an hour searching, but have not been able to come up with a solution. A code snippet may help clarify what I am seeking class SuperClass { get callingInstanceType() { return this.constructor.name } static get callingClassType() { return '....help here ...' } } class SubClass extends SuperClass { } let sc = new SubClass() console.log(sc

问题 New to JavaScript. Seeking some guidance on how to access the calling class name from a static method defined in the superclass using ES6 classes. I've spent an hour searching, but have not been able to come up with a solution. A code snippet may help clarify what I am seeking class SuperClass { get callingInstanceType() { return this.constructor.name } static get callingClassType() { return '....help here ...' } } class SubClass extends SuperClass { } let sc = new SubClass() console.log(sc

问题 This question already has answers here : Create object from string in JavasScript ECMAScript 6 (5 answers) Closed 20 days ago . I have a class, which depends on type of string, gets in in a swithc statement, and call to de new "class_name" related (constructor). But, I would like to know if there is a better way to solve this. It would be ideal if there is a way to call the builder independently, within a specific folder, of all the classes that exist. Project example: Types/_String.js Types/

问题 The example below is simplified. I have a getter method: class MyClass { constructor() {} get myMethod() { return true; } } which is processed by babel. And I want to mock it like this: var sinon = require('sinon'); var MyClass = require('./MyClass'); var cls = new MyClass(); var stub = sinon.stub(cls, 'myMethod'); stub.returns(function() { return false; }); But I get the following error: TypeError: Attempted to wrap undefined property myMethod as function And this happens on both version 1