Javascript scope addEventListener and this

Question

I am a C# developer experimenting with JavaScript and I\'m trying to get my head around the scope :)

I have the following code which contains an addEventListe

Answer 1

How about

function Keyboard() {
    this.keys = {};
    var self = this;
    this.handle_keydown = function(args) {
        self.keys[args.keyCode] = true;
    }
    this.listen = function() {
        window.addEventListener('keydown', this.handle_keydown);
    }
}
app.util.keyboard = new Keyboard();