Getting Started With JavaScript for Pythonistas (Summary)

Congratulations, you made it to the end of the course! The team’s day-one setup check now runs in JavaScript. It lives in onboarding-check/, next to a package.json that makes every .js file in the folder an ES module. It prints the Node version, the operating system, the current folder, and the three next steps, the report a new developer pastes into the onboarding channel.

In this course, you learned how to:

• Install a current version of Node and check it with node -v
• Try expressions in Node’s REPL, and leave it with .exit or Ctrl+D
• Run a script with the node command and print with console.log()
• Make every .js file in a project an ES module with a package.json holding "type": "module"
• Read a stack trace from the top, where Node shows the failing line, the error, and then the calls, innermost first
• Recognize undefined where Python would raise an error, and trace a crash back to where the undefined came from

The traps in this course were Python habits carried into JavaScript. Some stop with an error, but the worst ones run without one, like the OS: undefined that reached the report when process.platform was misspelled.

Keep the Habits That Carry Over