Getting Clojure

Arithmetic

Another thing that usually comes early in learning a programming language is figuring out how to do basic arithmetic. Clojure’s approach to doing math is refreshingly—and perhaps a little disconcertingly—simple. To see what this means, let’s add a couple of numbers together:

(+ 1900 84)

Run the expression in that example through the REPL and you will get back 1984. You do multiplication, subtraction, and division in the same way:

(* 16 124)   ; Gives you 1984.
(- 2000 16)  ; 1984 again.
(/ 25792 13) ; 1984 yet again!

As you might expect, you can assemble these basic math operations into arbitrarily complex expressions. Thus you can get the average of 1984 and 2010 with this:

(/ (+ 1984 2010) 2)

Arithmetic in Clojure can be ...