Question

i’m trying to encapsolate my code inside an immediate function that later on will be accessed via the global variable x and act like a “module”.

code:

var x = (function () {

    console.log(x); // undefined
    console.log(this); // undefined

})();

But I don’t understand why I cant use this to refer to the function itself.

EDIT:

the immediate function is inside another function in strict mode ("use strict")

Answer 1

there’s a funny thing that happens when a function is executed within a function, or handed as a callback to another function that is handled in strict mode

here’s a demo, and watch the console

function foo(){
    'use strict';

    (function(){
        //undefined in strict mode
        console.log('in foo, this is: '+this);  
    }());

}

function bar(){

    (function(){
        //DOMWindow when NOT in strict mode
        console.log('in bar, this is: '+this); 
    }());

}

foo();
bar();​

so if that code is executed as a callback within another function that is in strict mode, this will not refer to the global window, but rather it will be undefined.