Question

So I see plenty of JavaScript code out there that uses “new” when making constructors. After reading part of JavaScript the Good Parts it seems that using “new” isn’t the cat’s pajamas. That was 4 years ago though… Is it still not recommended? What is the current standard?

Answer 1

Since when is new not recommended? D. Crockford has a valid point and a strong opinion but new is part of the language and it’s very much being used in many projects. new is part of the prototype inheritance model, and must be used to create new instances with a constructor function. Crockford points out a purely functional approach using the this context appropriately and return this to be able to inherit properties and methods between children objects. It’s a different solution to a common problem, but it doesn’t mean that new shouldn’t be used. In fact, one of the most copy/pasted JS snippets of all times is Crockford’s, the object.create polyfill, and it uses new:

if (typeof Object.create !== 'function') {
    Object.create = function (o) {
        function F() {}
        F.prototype = o;
        return new F();
    };
}