Introduction

This tutorial covers the basic elements of the Julia programming language. Most of the topics are taken from the official Julia documentation, check it for more detailed information.

Get started

The three main ways of using Julia are by writing commands directly in an interactive session, working with scripts, and working with notebooks. These are described below.

An interactive session

You can start using Julia on an interactive session by running julia from the command line. Once it is opened, you can execute Julia commands:

10 ^ 2

The session can be closed using CTRL-D or typing exit() inside Julia session.

Scripts

Julia scripts have extension *.jl. An script is just a file containing Julia commands. The script src/00-file.jl has the following commands:

x = [1, 3]
for i in x
    println(i)
end

We can evaluate this script using the function include.

include("src/00-file.jl")

A custom script with optional arguments can also be evaluated non-interactively (on a terminal) providing the script name as a first argument to the julia command.

julia script.jl arg1 arg2

Note that the script name is passed to the global variable PROGRAM_FILE. Similarly, the arguments are passed to ARGS.

As an example the script src/00-script.jl prints the filename and the arguments provided.

println(PROGRAM_FILE)
for x in ARGS
    println(x)
end

We can execute it as follows:

julia src/00-script.jl 1 10 100

Notebooks are an interactive way to execute code, but also add formated markdown text. You are probably looking at this file as a notebook. In this course, we will mainly use notebooks given that it is easier for students to start up.