Auto-subscription with $ prefix in Svelte - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the $ prefix do in Svelte when used with a store variable?

The $ prefix automatically subscribes to the store and gives you the current value. It updates the value reactively when the store changes.

beginner

How do you use the $ prefix to read a store value inside a Svelte component?

You write $storeName in your script or markup. For example, if you have a store called count, use $count to get its current value reactively.

intermediate

Can you assign a new value to a store using the $ prefix in Svelte?

Yes! You can write $storeName = newValue to update the store's value. This automatically updates all parts of the app using that store.

beginner

What happens if you use a store variable without the $ prefix in Svelte?

Without the $, you get the store object itself, not its value. You would need to subscribe manually to get updates.

beginner

Why is auto-subscription with $ prefix helpful in Svelte?

It simplifies code by removing manual subscription and unsubscription. It keeps your UI in sync with store values automatically and cleanly.

In Svelte, what does writing $count do if count is a store?

A Gets the current value of the count store reactively

B Creates a new store named count

C Deletes the count store

D Assigns a new value to count store

Using $count reads the current value of the store and updates reactively when the store changes.

How do you update a writable store named 'score' using the $ prefix?

A $score = 10

B score.set(10)

C score = 10

D $score.set(10)

You can assign a new value directly with $score = 10; this updates the store reactively.

What do you get if you use 'count' without $ in Svelte?

A An error

B The current value of the store

C The store object itself

D A new store

Without $, you get the store object, not its value.

Which of these is true about auto-subscription with $ prefix?

A It requires manual subscription and unsubscription

B It automatically unsubscribes when the component is destroyed

C It only works with readable stores

D It disables reactivity

Svelte handles subscription and unsubscription automatically with the $ prefix.

Why is using $ prefix recommended in Svelte for stores?

A Makes stores read-only

B Prevents store updates

C Requires manual cleanup

D Simplifies code and keeps UI reactive

The $ prefix makes code simpler and keeps the UI in sync with store changes automatically.

Explain how the $ prefix works with stores in Svelte and why it is useful.

Think about how $storeName gives you the current value and updates automatically.

Describe the difference between using a store variable with and without the $ prefix in Svelte.

Consider what you get and how reactivity works in each case.