Given is the following code:  function two() {     return "success"; }  function one() {     two();     return "fail"; }   If you test the code by calling function one(), you will always get "fail".  The question is, how can I...

I am on Day 3 of learning JavaScript. I cames across this code:  class B {     constructor(name) {         this.name = name;     }      printn() {         return this.name;     } }  class A extends B {     constructor(name, age) {         super(name)...

I'm learning react from the docs, but not sure what the super() does in this example. Usually, doesn't it take the arguments that are passed to making a new instance and then calls React.Component's constructor method to incorporate these...

Consider the following code:  class Base {    constructor() {       let _myPrivateData = 'Base';       this.print = () => { console.log(_myPrivateData); };    } };  class Derived extends Base {    constructor() {        super();       this...

I want to test a method 'foo' that calls its super method 'foo':  foo(){      super.foo();      //do some extra stuff }   If it would reference another method from the same class, e.g.  foo(){      this.baa();      //do some extra stu...

The MDN page about set seems to state that an      [ECMAScript 2015] setter must not appear in an object literal ... with a   data entry for the same property.   However when using the super keyword this no longer seems to apply.  class Foo {     con...

As there are no private method support yet in Javascript, I usually simply declare a normal function outside of class body and provide this as argument:  class Foo {     constructor() {         _doPrivateStuff(this);     } }  function _doPrivateStuff...

I would like to include multiple mixins within a view in Ember.js and more than one of the mixins and/or the view uses a same event (e.g. willInsertElement). I'm running Ember 1.4.0-beta.5.  I understand that the event in each mixin will be overr...

Lets say we have a class ABC:  class ABC{     constructor(param1, param2){         this.prop1 = param1;         this.prop2 = param2;     }     ABCMethod1(){         console.log(this.prop1 + ' ' + this.prop2);     } }   And one another class X...

I got a sensor class and a class which extends it. The constructors of both classes use async operations.   Base class:  /**  * Basic sensor class  */ class Sensor {   /**    * Constructor function    * @param {object} options - sensor options    * @...