I have a situation where I need to check if a constructor (X) has another constructor (Y) in its prototype chain (or is Y itself).  The quickest means to do this might be (new X()) instanceof Y. That isn't an option in this case because the const...

I'm building a Node.js app with Connect/Express.js and I want to intercept the  res.render(view, option) function to run some code before forwarding it on to the original render function.  app.get('/someUrl', function(req, res) {      res...

Given simple JS inheritance, what's the practical difference in the base function between these two examples?  In other words, when should a person choose to define a function on "this" instead of on the prototype (or the other way around...

I'm trying to get a deeper hold on prototypal inheritance and class creation (I know, there are other ways, but for the purpose of this I'm trying to grasp prototypes.) My question is: Using the following code example, is there a way to creat...

Background  I've been using the C preprocessor to manage and "compile" semi-large javascript projects with multiple files and build targets. This gives full access to C preprocessor directives like #include, #define, #ifdef, etc. from wit...

function F() {     return function() {         return {};     } }  var f = new F(); f instanceof F; // returns false   As far as I understand, if I want instanceof to work, I need to return this from the constructor. But I want the constructor to ret...

The following answer to this question does a great job explaining the differences between classical inheritance and prototypal inheritance. this was of interest to me to understand because I started working in Java, but moved over to Javascript.   In...

I want to convert an instance class to plain object, without losing methods and/or inherited properties. So for example:  class Human {     height: number;     weight: number;     constructor() {         this.height = 180;         this.weight = 180;...

Consider the following Javascript snippet,  var SuperClass = function(x){     this.x = x;     this.a = 5; };  var SubClass = function(x){ }  function IntermediateClass(){}; IntermediateClass.prototype = SuperClass.prototype; SubClass.prototype = new...

I have an existing prototype hierarchy and I want to modify it so that the hierarchy is kept intact but an additional prototype is added to then end of it. instanceof should return true for all prototypes.  I.e.: say I have B->A and I want to make...