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...

This example creates an object, freezes it, and then creates a new object from the frozen object. If the second object tries to change the test property, it can't. It remains frozen with the first object's value of 10.  //Create an object and...

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...

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In Douglas Crockford's JavaScript: The Good Parts he recommends that we use functional inheritance.  Here's an example:  var mammal = function(spec, my) {     var that = {};     my = my || {};      // Protected     my.clearThroat = function()...

If a variable is not available in a function when it's needed, then it's being looked for in the scope chain (which is a closure), but other times it's being searched for in the prototype chain. I am trying to wrap my head around which is...