Worker thread vs child process in Node.js - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new worker thread.

Node.js

const { Worker } = require('worker_threads');
const worker = new [1]('./worker.js');

Drag options to blanks, or click blank then click option'

AWorker

BChildProcess

CThread

DProcess

Attempts:

3 left

💡 Hint

Common Mistakes

Using ChildProcess instead of Worker for threads

Using lowercase 'worker' which is not a class

Confusing Process with Worker

In Node.js, Worker is used to create a new worker thread.

2fill in blank

medium

Complete the code to spawn a child process using Node.js.

Node.js

const { spawn } = require('child_process');
const child = spawn('[1]', ['-lh', '/usr']);

Drag options to blanks, or click blank then click option'

Anode

Bthread

Cworker

Dls

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'node' which runs Node.js, not a shell command

Using 'worker' or 'thread' which are not shell commands

The spawn function runs a command; here, ls lists directory contents.

3fill in blank

hard

Fix the error in the worker thread message listener.

Node.js

worker.on('message', ([1]) => {
  console.log('Received:', data);
});

Drag options to blanks, or click blank then click option'

Adata

Bmsg

Cmessage

Devent

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different parameter name than the one used inside the function

Using 'msg' or 'message' but logging 'data'

The parameter name must match the variable used inside the function. Here, data is used, so the parameter should be data.

4fill in blank

hard

Fill both blanks to send a message from the main thread to the worker.

Node.js

worker.[1]({ text: 'Hello' });
worker.[2]('exit', () => console.log('Worker exited'));

Drag options to blanks, or click blank then click option'

ApostMessage

Bsend

Con

Demit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'send' which is for child processes, not worker threads

Using 'emit' instead of 'on' to listen for events

Use postMessage to send data to a worker thread, and on to listen for events like 'exit'.

5fill in blank

hard

Fill all three blanks to create a child process and handle its output.

Node.js

const { [1] } = require('child_process');
const child = [2]('node', ['script.js']);
child.stdout.on('[3]', data => console.log(`Output: ${data}`));

Drag options to blanks, or click blank then click option'

Aspawn

Cdata

Dexec

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'exec' instead of 'spawn' which behaves differently

Listening for wrong event names like 'output' or 'message'

Import spawn from 'child_process', use it to create the child process, and listen for 'data' events on stdout.