onMount in Svelte - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the onMount function from Svelte.

Svelte

import { [1] } from 'svelte';

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

AonMount

BuseEffect

CcomponentDidMount

DonInit

Attempts:

3 left

💡 Hint

Common Mistakes

Using React lifecycle functions like useEffect or componentDidMount instead of onMount.

Trying to import a function that doesn't exist in Svelte.

The onMount function is imported from 'svelte' to run code when the component is first added to the page.

2fill in blank

medium

Complete the code to run a function when the component mounts.

Svelte

onMount(() => { [1] });

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

AsetTimeout()

Breturn () => {}

Cconsole.log('Mounted!')

Dexport default

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to export inside the onMount callback.

Using setTimeout without a function.

The function inside onMount runs when the component appears. Logging 'Mounted!' shows this.

3fill in blank

hard

Fix the error in the onMount usage by completing the code.

Svelte

onMount([1] () => {
  console.log('Ready');
});

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

Aasync

Bawait

Cfunction

Dexport

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'await' before the function keyword.

Trying to export inside the callback.

You can make the onMount callback async to use await inside it if needed.

4fill in blank

hard

Fill both blanks to correctly import and use onMount with a cleanup function.

Svelte

import { [1] } from 'svelte';

onMount(() => {
  const id = setInterval(() => console.log('Tick'), 1000);
  return () => clearInterval([2]);
});

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

AonMount

Bid

Cinterval

DsetInterval

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable name in clearInterval.

Importing a wrong function name.

Import onMount to run code on mount. The cleanup function clears the interval using the variable id.

5fill in blank

hard

Fill all three blanks to create a reactive variable updated on mount.

Svelte

import { [1] } from 'svelte';

let count = 0;

onMount(() => {
  const timer = setInterval(() => {
    count [2] count + 1;
  }, 1000);
  return () => clearInterval([3]);
});

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

AonMount

B=

Ctimer

D+=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+=' instead of '=' for updating count (works but not the intended answer).

Clearing interval with wrong variable.

Import onMount to run code on mount. Use = to update count. Clear the interval using timer.