I'm really digging this double arrow syntax right now

ES6 is great. Makes code so much cleaner and easier to write :D

Correct me if I'm wrong, but
Hey is a function (name) that exists of an anonymous function(activity)?

Hey is a function that accepts name and returns a function that accepts activity.

hey = function(name) {
return function(activity){}
}

@ImJosh Look at functions as objects.
heyJosh = hey("Josh")

heyJosh is now a function(activity)

@incognito @ImJosh sorry, I use them inside a React.component so I don’t put const in front of variables.
This is same as function(name){ return function(activity){ ... }}. If you interested, type it in and take a look at Babel transform result.
Why is it useful?
<button onClick={this.onClick(param)} />
So I can pass some parameters into onClick event, and still receive event

@A4Abhiraj you are right!👍

(a=>a.bind(0,a))(a=>a.bind(0,a))()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()
// My favourite line of code ever

@ImJosh It's called currying.

@Root immediately thought currying when I saw the screenshot!