`this` in JavaScript

If you have ever got your hands dirty with JavaScript, you know that this doesn't always refer to what you might expect.

Basically, it's not guaranteed, ever.

.bind()

.call(), apply()

with()

() => { ... }  vs. function(){ ... }

subscribe() -> subscriber, hit in Angular which started reloading the whole app because onSubmit wasn't called.

D3 -> see docs

https://medium.com/@dan_abramov/how-to-use-classes-and-sleep-at-night-9af8de78ccb4#.ehxm9853t