Clojure - Defining a Function

A function is defined by using the defn macro. Following is the general syntax of the definition of a function.

Syntax

(defn functionname
   optional documentation string
   [arguments]
   (code block))

Functions can have documentation strings, which is good to describe what the function actually does.

Example

Following is a simple example of a function.

(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (def x 1)
   (def y 1.25)
   (def str1 "Hello")
   (println x)
   (println y)
   (println str1))
(Example)

In the above example, the name of the function is Example.

Output

1
1.25
Hello