How to Use process.exit in Node.js: Syntax and Examples

In Node.js, use process.exit(code) to stop the program immediately with an optional exit code. A code of 0 means success, while any other number signals an error or specific status.

Syntax

The process.exit() method stops the Node.js process immediately. It takes one optional argument:

• code (number): The exit status code. 0 means success, any other number indicates an error or specific exit reason.

If no code is provided, it defaults to 0.

javascript

process.exit(code);

Example

This example shows how to exit a Node.js program with a success code 0 and an error code 1. The program prints a message before exiting.

javascript

console.log('Program started');

// Exit with success code 0
process.exit(0);

// This line will not run
console.log('This will not print');

Output

Program started

Common Pitfalls

Common mistakes when using process.exit() include:

• Calling process.exit() before asynchronous tasks finish, causing data loss.
• Not providing an exit code, which defaults to 0 and may hide errors.
• Expecting code after process.exit() to run, but it never does.

Always ensure all important work is done before calling process.exit().

javascript

/* Wrong way: Exiting before async task finishes */
setTimeout(() => {
  console.log('Async task done');
}, 1000);
process.exit(0); // Exits immediately, async task never runs

/* Right way: Exit after async task */
setTimeout(() => {
  console.log('Async task done');
  process.exit(0); // Exit after task
}, 1000);

Output

Async task done

Quick Reference

Remember these tips when using process.exit():

• Exit code 0: Success
• Non-zero exit codes: Indicate errors or special conditions
• Use before exit: Finish all async work
• Code after exit: Will not run

Key Takeaways

Use process.exit(code) to stop Node.js immediately with an exit code.

Exit code 0 means success; non-zero codes signal errors or special states.

Never call process.exit() before finishing asynchronous tasks.

Code after process.exit() will not execute.

Always provide an exit code to clearly indicate program status.