Derived store otomatis menghitung nilai berdasarkan store lain.

Membuat Derived Store

import { derived } from "svelte/store"
import { count } from "./stores.js"

export const doubled = derived(count, $count => $count * 2)

Multiple Dependencies

import { derived } from "svelte/store"

export const total = derived(
  [harga, jumlah],
  ([$harga, $jumlah]) => $harga * $jumlah
)

Menggunakan

<script>
  import { count } from "./stores.js"
  import { doubled } from "./derived.js"
</script>

<p>{$count} x 2 = {$doubled}</p>

Derived store read-only — nilainya selalu dihitung dari source store.