You have some nice functional stuff. You can define a function on a primitive type like an integer. This enables you to have code like 400.times(doX). doX is a

You have some nice functional stuff. You can define a function on a primitive type like an integer. This enables you to have code like 400.times(doX). doX is a function. Functions as first class citizens are nice. If you have a function as a final argument, you can change this: something(a, b, { }) to something(a, b) { }. Basically, you just put your anonymous function on the outside of the parenthesis. I think the book's example was something along the lines of sort(arr) { $1 > $2 }. I think that $1 is some kind of default specifier for the first param and $2 for the second, but I'm not sure.