Introducing Julia

Introduction

The Julia programming language is easy to use, fast, and powerful. This wikibook is intended as an introduction to the language for the less experienced and occasional programmer. For more learning materials, including links to books, videos, articles/blogs and notebooks, refer to the learning section at Julia's official site. See Jobs for types of jobs and companies using Julia.

The official Julia documentation is the authoritative guide, and you should refer to it as often as possible as you learn. It's the "reference" guide both for the language itself and for the set of standard packages (the "standard library") that are provided as part of the basic installation.

A feature of Julia is the extensive use of add-on packages to add functionality and features, and to extend the syntax of built-in functions. Good places to look for packages (which are free to download from github.com) include the JuliaHub site. Packages provide their own documentation and many provide extensive tutorials.

The Julia community has established a good ethos of encouraging participation in the development of the language on github. The advantage of this wikibook is that it's made and edited by the Julia community – you can edit anything at any time. If you find something that's wrong, or unclear, feel free to correct it, or add examples. (Your first few edits are reviewed, just in case you have less than good intentions. And, as with the Wikipedia, you should expect your writing to be edited by others!) The focus should be largely on the new user, rather than the computer science expert.

Outline

Getting started

some introductory words, installation, paths, and various bits of magic

The REPL

Using the REPL; Julia as a calculator; getting help

Arrays and tuples

Storing data – Arrays and tuples; the core of Julia and scientific programming

Types

a quick introduction to types, the way to organize your code and the secret to making your programs fast

Controlling the flow

loops and decisions; ifs and elses

Functions

functions and methods; multiple dispatch

Dictionaries and sets

storing data in dictionaries and sets

Strings and characters

working with strings

Working with text files

reading data from text files; elementary file processing

Working with dates and times

working with date and time functions

Plotting

Plotting; an introduction to some of the plotting packages

Metaprogramming

metaprogramming, expressions and macros

Modules and packages

how Julia code is organized, and should be developed

DataFrames

data frames; organizing data in tables

Migrating From Other Languages

Julia for users of other programming languages

Introducing Julia/Games

Julia games, and some tools to make games

External links

• The Julia manual – the official rulebook: current and in-development documentation is available here.
• The JuliaLang Discourse - the main Julia programming language discussion forum
• Julia Forem Community
• JuliaHub – a service that searches all registered Julia packages, code, and documentation.
• Julia.jl – a manually curated taxonomy of Julia packages
• A Month of Julia – 38 blog posts about using Julia.