Action parameters in Svelte - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are action parameters in Svelte?

Action parameters are extra values you can pass to a Svelte action to customize its behavior when you use it on an element.

beginner

How do you pass parameters to a Svelte action?

You pass parameters by adding a second argument to the action in the template, like <div use:myAction={param}>.

intermediate

What is the shape of a Svelte action function that uses parameters?

It is a function that takes two arguments: the node (element) and the parameters object, like function myAction(node, params) { ... }.

intermediate

How can an action respond to parameter changes in Svelte?

The action can return an object with an update function that Svelte calls when parameters change, allowing the action to adjust behavior.

beginner

Why is it useful to use action parameters in Svelte?

They let you reuse the same action with different settings on different elements, making your code cleaner and more flexible.

How do you pass parameters to a Svelte action?

A By adding a second argument in the use directive, like use:action={params}

B By calling the action function manually in script

C By setting a global variable

D By using a special Svelte store

You pass parameters directly in the template with use:action={params}.

What arguments does a Svelte action function receive?

A Node and parameters

B Parameters only

C Only the node (element)

D No arguments

The action function receives the node and the parameters as arguments.

What should an action return to handle parameter updates?

A An update function only

B An object with update and destroy functions

C A cleanup function only

D Nothing

An action returns an object with update and destroy functions to handle changes and cleanup.

If you want to change an action’s behavior when parameters change, what do you do?

A Recreate the element

B Ignore parameter changes

C Use the update function returned by the action

D Use a reactive statement

The update function lets the action respond to parameter changes.

Why use parameters with Svelte actions?

A To avoid writing any JavaScript

B To create new components

C To style elements

D To make actions reusable with different settings

Parameters let you reuse the same action with different options on different elements.

Explain how to pass and use parameters in a Svelte action.

Think about how you customize behavior for different elements.

Describe why action parameters improve code reuse in Svelte.

Imagine using one tool for many jobs by changing its settings.