Confusing JavaScript statement: "var x = new this();"

Question

I thought I understood the concept of the JavaScript prototype object, as well as [[proto]] until I saw a few posts regarding class inheritance.

Firstly, "JavaScript OOP - the smart way" at http://amix.dk/blog/viewEntry/19038

See the implementation section:

var parent = new this('no_init');

And also "Simple JavaScript Inheritance" on John Resig's great blog.

var prototype = new this();

What does new this(); actually mean?

This statement makes no sense to me because my understand has been that this points to an object and not a constructor function. I've also tried testing statements in Firebug to figure this one out and all I receive is syntax errors.

My head has gone off into a complete spin.

Could someone please explain this in detail?

Answer 1

In a javascript static function, you can call new this() like so,

var Class = function(){}; // constructor
Class.foo = function(){return this;} // will return the Class function which is also an object

Therefore,

Class.foo = function(){ return new this();} // Will invoke the global Class func as a constructor

This way you get a static factory method. The moral of the story is, not to forget functions are just like any other objects when you are not calling them.