JavaScript Exercises

These JavaScript exercises are intended to complement the JavaScript content on The Odin Project (TOP). They should only be done when instructed during the course of the curriculum.

Note: The generator-exercise file is not actually an exercise; it is a script that generates exercises. It was created to help efficiently write these exercises.

Contributing

If you have a suggestion to improve an exercise, an idea for a new exercise, or notice an issue with an exercise, please feel free to open an issue after thoroughly reading our contributing guide in our main TOP repo.

How To Use These Exercises

Before you start you should have a few things installed on your machine:

1. NPM. We should have installed NPM already in this Installing Node.js lesson. Just in case you need to check, type npm --version in your terminal. If you get back Command 'npm' not found, but can be installed with:, do NOT follow the instructions in the terminal to install with apt-get. (This causes permission issues.) Instead, go back to the installation lesson and install Node with NVM by following the instructions there.
2. A fork and clone of this repository. To learn how to fork a repository, see the GitHub documentation on how to fork a repo.
   • Copies of repositories on your machine are called clones. If you need help cloning to your local environment you can learn how from the GitHub documentation on cloning a repository.
3. Jest. After cloning this repository to your local machine, go into the newly created directory (cd javascript-exercises) and run npm install. This will install Jest and set up the testing platform based on our preconfigured settings.

Each exercise includes 3 files: a markdown file with a description of the task, an empty (or mostly empty) JavaScript file, and a set of tests. To complete an exercise, you'll need to go to the exercise directory with cd exerciseName in the terminal and run npm test exerciseName.spec.js. This should run the test file and show you the output. When you first run a test, it will fail. This is by design! You must open the exercise file and write the code needed to get the test to pass.

Some of the exercises have test conditions defined in their spec file that are defined as 'test.skip' compared to 'test'. This is purposeful. After you pass your first 'test', you will change the next 'test.skip' to 'test' and test your code again. You'll do this until all conditions are satisfied. ALL TESTS MUST PASS AT THE SAME TIME.

Note: Due to the way Jest handles failed tests, it may return an exit code of 1 if any tests fail. NPM will interpret this as an error and you may see some npm ERR! messages after Jest runs. You can ignore these, or run your test with npm test exerciseName.spec.js --silent to supress the errors.

The first exercise, helloWorld, will walk you through the process in-depth.

Debugging

To debug functions, you can run the tests in the Visual Studio Code debugger terminal. You can open this by clicking the "Run and Debug" icon on the left or pressing ctrl + shift + D, then clicking JavaScript Debug Terminal. You will be able to set breakpoints as you would in the Chrome DevTools debugger. You can run npm test exerciseName.spec.js to then execute your code up until your breakpoint and step through your code as necessary. NOTE: To take advantage of the debugger, you MUST run the script in the debugger terminal, not the bash or zsh terminal.

Solutions

Solutions for these exercises can be found in this repo on the 'solutions' branch.