Meaning of “this” in node.js modules and functions

Question

I have a JavaScript file which is loaded by require.

// loaded by require()

var a = this; // \"this\" is an empty object
this.anObject = {name:         


        

Answer 1

To understand this, you need to understand that Node.js actually wraps your module code in to a function, like this

(function (exports, require, module, __filename, __dirname) {
    var test = function(){
        console.log('From test: '  + this);
    };
    console.log(this);
    test();
});

Detailed explanation can be found in this answer.

---

Now, this wrapped function is actually invoked like this

var args = [self.exports, require, self, filename, dirname];
return compiledWrapper.apply(self.exports, args);

So, this, at the module level, is actually the exports object.

You can confirm that like this

console.log(this, this === module.exports);
// {} true