Here is a simple function definition that takes a number and divides it by two
(defn half-a-number "Divide a given number by 2" [number] (/ number 2))
Once you have defined a function, you can call it by using the function name as the first element of a list
Breaking down the defn syntax
defn is what we call a macro, it is a simpler way to write clojure code that does the same thing.
You can think of defining a function with
defn as two steps
1) Give the function a name - using the
2) Define the functions behaviour and arguments it takes - using the
Here is the same function if you typed it out in full
(def half-a-number (fn [number] (/ number 2)))
is it too soon to show macroexpand ?