setTimeout and clearTimeout in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to schedule a function to run after 2 seconds.

Node.js

setTimeout(() => { console.log('Hello!'); }, [1]);

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

A2000

B2

C0.002

D20

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2 instead of 2000 for 2 seconds delay.

Using 0.002 which is 2 microseconds, too short.

The setTimeout delay is in milliseconds, so 2000 means 2 seconds.

2fill in blank

medium

Complete the code to cancel a scheduled timeout using its ID.

Node.js

const timerId = setTimeout(() => { console.log('Run later'); }, 3000);
clearTimeout([1]);

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

AsetTimeout

B3000

Cnull

DtimerId

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the delay time (3000) instead of the timer ID.

Passing null or the function name.

You must pass the timer ID returned by setTimeout to clearTimeout to cancel it.

3fill in blank

hard

Fix the error in the code to properly cancel the timeout.

Node.js

let id = setTimeout(() => console.log('Oops'), 5000);
clearTimeout([1]);

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

AtimeoutId

B5000

Cid

DsetTimeout

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong variable name like timeoutId.

Passing the delay time (5000) instead of the ID.

The variable id holds the timer ID and must be passed to clearTimeout.

4fill in blank

hard

Fill both blanks to schedule a message and then cancel it before it runs.

Node.js

const [1] = setTimeout(() => console.log('Bye!'), 4000);
[2]([1]);

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

Atimer

BclearTimeout

CsetTimeout

Dtimeout

Attempts:

3 left

💡 Hint

Common Mistakes

Using setTimeout instead of clearTimeout to cancel.

Not storing the timer ID in a variable.

Store the timer ID in timer and pass it to clearTimeout to cancel.

5fill in blank

hard

Fill all three blanks to create a timeout, cancel it, and then schedule a new one.

Node.js

const [1] = setTimeout(() => console.log('First'), 3000);
[2]([1]);
const [3] = setTimeout(() => console.log('Second'), 3000);

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

AfirstTimer

BclearTimeout

CsecondTimer

DsetTimeout

Attempts:

3 left

💡 Hint

Common Mistakes

Not cancelling the first timer before creating the second.

Using the same variable name for both timers.

Use firstTimer to store the first timeout, cancel it with clearTimeout, then create secondTimer for the new timeout.