Node.js

REPL Commands

Use Node.js's REPL (Read-Eval-Print Loop) for interactive JavaScript execution. Test code snippets, explore APIs, and prototype quickly without creating files.

5 commands

Pro Tips

Use '.load filename.js' in the REPL to load and execute a file, making its variables available.

Press Tab twice for autocompletion. Type 'global.' + Tab to explore available globals.

The '_' variable holds the last expression result. Use it to chain operations without assigning.

Common Mistakes

REPL mode enables top-level await by default, but regular .js files need 'type: module' in package.json.

REPL history is saved to ~/.node_repl_history. Be careful with sensitive data like API keys.

Commands

Start REPL

$ node

Start interactive Node.js REPL.

Force interactive

$ node -i

Force REPL even without TTY.

REPL help

$ .help

Show REPL commands (.break, .clear, .exit, etc.).

Load file in REPL

$ .load filename.js

Load JavaScript file into REPL session.

Save REPL history

$ .save history.js

Save all evaluated commands to file.