process.exit and exit codes in Node.js - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the exit code of this Node.js script?

Consider this Node.js script. What exit code will the process return when it finishes?

Node.js

process.exit(5);

A 1

B 0

C 5

D undefined

💡 Hint

The number passed to process.exit() is the exit code.

process.exit(5) immediately stops the Node.js process and returns exit code 5 to the operating system.

❓ Predict Output

intermediate

What happens if you call process.exit() without arguments?

What exit code does Node.js use if process.exit() is called with no arguments?

Node.js

process.exit();

A 1

B NaN

C undefined

D 0

💡 Hint

Default exit code when none is specified is zero.

Calling process.exit() without arguments exits with code 0, which means success.

❓ component_behavior

advanced

What will this script output before exiting?

Analyze this script. What will it print before the process exits?

Node.js

console.log('Start');
process.exit(2);
console.log('End');

A End

B Start

C Start\nEnd

D No output

💡 Hint

process.exit stops the process immediately.

The first console.log prints 'Start'. Then process.exit(2) stops the process immediately, so 'End' is never printed.

📝 Syntax

advanced

Which option causes a syntax error?

Which of these process.exit calls will cause a syntax error in Node.js?

A process.exit 1;

B process.exit('1');

C process.exit();

D process.exit(0);

💡 Hint

Check the syntax for calling functions in JavaScript.

process.exit 1; is missing parentheses and will cause a syntax error.

🔧 Debug

expert

Why does this script exit?

This script calls process.exit(0) inside a setTimeout. Why does the process exit?

Node.js

setTimeout(() => {
  process.exit(0);
}, 1000);

setInterval(() => {
  console.log('Running');
}, 500);

A Because setTimeout is delayed, but process.exit is called after 1 second, the process exits.

B Because process.exit is asynchronous and delayed, the process stays alive.

C Because setInterval prevents process.exit from stopping the process.

D Because setInterval keeps the event loop alive, process.exit is never called.

💡 Hint

process.exit stops the process immediately when called.

The setTimeout calls process.exit(0) after 1 second, which stops the process immediately, even if setInterval is running.