Last Updated: February 25, 2016
· sativaware

Hello world in Clojure

Firstly, Download & Install leiningen - which will help you build your Clojure project.

Create a new project using leiningen's lein command:

$ lein new hello-world

#Generating a project called hello-world based on the 'default' template.
#To see other templates (app, lein plugin, etc), try `lein help new`.

Edit the project.clj file that was created for you:

$ cd hello-world

$ nano project.clj

Overwrite the contents of project.clj with the following code

(defproject hello-world "0.1.0-SNAPSHOT"
  :main hello-world.core
  :dependencies [[org.clojure/clojure "1.5.1"]])

Next, edit the main source file of your project:

$ nano src/hello_world/core.clj

Overwrite the contents of src/helloworld/core.clj_ with the following code:

(ns hello-world.core)

(defn -main [& args]
  (println "Hello, World!"))

You are now able to run your app:

$ lein run
# Hello, World!

What this gives you is a Clojure project that prints "Hello, World!" to the terminal - all that remains is to let your imagination take over.

What is next ??

Try out some of the Clojure code in the articles below by editing the src/hello_world/core.clj file and running $ lein run