You can develop your Julia programs by typing directly in the REPL. Note that the history of everything you type in the REPL is stored, even across restarts. You can access this history using the up-arrow key, or by using ctrl-r for searching.
Even though you can always scroll up to see code you’ve already written in a REPL, this is not a good way to review or save past work once you start writing longer programs. If you want a more graphical environment that also saves your programs, you can use Julia from within your favorite text editor: Visual Studio Code, Vim, Emacs, IntelliJ IDEA. Minimally, a text editor like Vim or Notepad will allow you to create a document where you can write programs but without automatically adding a bunch of formatting information. (Microsoft Word and Apple Pages store a lot more information about your document than just the text you’ve written, and this is bad for writing programs.)
To make coding easier, there are lots of “integrated development environments” (IDEs) out there that offer more than a simple text editor. These IDEs will allow you not only to write and store programs you’ve written, but also to run them, making it easier to test and experiment as you write. If you don’t yet have a favorite editor or IDE, we would suggest using the Atom code editor, along with Julia plugin for Atom, called Juno. Use the instructions here to install Atom and Juno. Juno lets you edit and run Julia code within a single environment.
Packages are downloaded using a package manager built into the Julia standard library. You can interact with the package manager in a couple of ways. The simplest is to press
] (the right square bracket) on your keyboard when you are at the REPL, which will put the REPL into pkg mode.
In this mode, you type package management commands directly into the REPL. For example,
add PackageName will add a package to your local environment, and
rm PackageName will remove it. Using the package manager will also typically manage the package’s dependencies for you; this means the package manager makes sure your computer/environment has everything it needs in order to run the package you want to install. A video showing how to use the package manager in more detail can be seen on our youtube channel.
Programming is fun and exciting. The Julia programming language is no exception. While it is always best to try to answer a question yourself if you can, feel free to ask someone else more experienced! Take a look at the Julia Community tab on the website to find all the places you can connect and get help in the Julia Community.