Svelte has a few built-in store functions , one of them being the writable store .

We use them by importing them from "svelte/store" like this:

import { writable, readable } from "svelte/store";

writable is a store where we can both read and write , and readable is a store that is read only .

Both of these stores have a method called subscribe that allows you to subscribe to the store .

The writable store has a method called set that allows you to set (and update) the value .

<script>
	import Input from "./Input.svelte";
	import Output from "./Output.svelte";
</script>

<Input />
<Output />

As you can see we could remove a lot of code by using the built in writable store functionality.