You can still attach a method on a class‘ prototype; after-all, classes are just syntactic sugar over a “functional object”, which is the old way of using a function to construct objects. Since you want to use ES6, I’ll use an ES6 import. Minimal effort, using the prototype: import getColor from ‘path/to/module’; class Car { … Read more
Classical inheritance is about extending types of things. Say you have a class, like Bike. When you want extend the behaviour, you have to design a new type of bike (like MotorBike). It’s like building a factory – you make lots of blueprints, and blueprints that reference those blueprints, but in order to ride one … Read more
Think of it like this. MyConstructor is a function object, so it was created by Function; therefore its [[Prototype]] (or __proto__) is identical to Function.prototype. In the same way, var myObj = new MyConstructor() creates an object myObj with a [[Prototype]] identical to MyConstructor.prototype. To put it another way, functions have a prototype property, and … Read more
Please don’t implement any other version because it will eat all your memory in your app: var Player = function(){this.__gold = 0}; Player.prototype = { get gold(){ return this.__gold * 2; }, set gold(gold){ this.__gold = gold; }, }; var p = new Player(); p.gold = 2; alert(p.gold); // 4 If 10000 objects are instantiated: … Read more
Javascript’s inheritance is prototype based, so you extend the prototypes of objects such as Date, Math, and even your own custom ones. Date.prototype.lol = function() { alert(‘hi’); }; ( new Date ).lol() // alert message In the snippet above, I define a method for all Date objects ( already existing ones and all new ones … Read more
I just wanted to point out that sometimes this error happens because a function has been used as a high order function (passed as an argument) and then the scope of this got lost. In such cases, I would recommend passing such function bound to this. E.g. this.myFunction.bind(this);
TL;DR – You can’t do that, your initial version of bitSet is how you need to define it. You’ll need to save its return value when you use it, e.g., x = x.bitSet(2). You can create your own mutable number object, though, if you like. (More on that below.) Just for clarity (you probably know … Read more
I recently had (another) brainwave, and I think I found a better way of augmenting the event prototype. Strictly speaking, the Event prototype is not accessible in IE (<9), but it is, I found out accessible if you work your way back from an instance (well, the instance: window.event). So here’s a snippet that works … Read more
Explanation So first, your two lines of code create a function, obj, and assign to it’s prototype {x: 5}. When you create an instance of this object, it seems to have an internal reference to the prototype that existed when it was new‘d. After this, you reassign the prototype to {y: 6} which does not … Read more
Quoting Douglas Crockford from the Good Parts book (page 47), to answer the title of this question: If the new operator were a method instead of an operator, it could be implemented like this: Function.method(‘new’, function () { // Create a new object that inherits from the // constructor’s prototype. var that = Object.create(this.prototype); // … Read more