createStore

stable

Create a state store

Creates a new store instance with get, set, subscribe, and destroy methods.

Signature

createStore<T>(initializer: T | StateCreator<T>): Store<T>

Parameters

initializer

T | (set, get) => TRequired

Either a raw initial state object or a function that receives set and get and returns the initial state object.

Returns

Store<T>

A store instance with get, set, subscribe, and destroy methods

Examples

Raw Object

The simplest way to create a store for data-only state:

import { createStore } from 'qortex-store';

const userStore = createStore({ 
  name: 'John', 
  loggedIn: false 
});

// Update via external set
userStore.set({ loggedIn: true });

Initializer Function (Set/Get)

Use an initializer to define actions that have access to current state and updates:

const counterStore = createStore((set, get) => ({
  count: 0,
  // Use get() to read current state
  increment: () => set({ count: get().count + 1 }),
  // Use functional updates for atomic changes
  decrement: () => set((s) => ({ count: s.count - 1 })),
  // Access other state properties within actions
  resetIfHigh: () => {
    if (get().count > 10) set({ count: 0 });
  }
}));

get()

Read the current state snapshot at any time:

const state = counterStore.get();
console.log(state.count); // 0

state.increment();
console.log(counterStore.get().count); // 1

set() — All Variants

set supports partial merging, functional updates, and full replacement:

const store = createStore({ a: 1, b: 2 });

// 1. Partial Merge (default)
store.set({ a: 10 }); // { a: 10, b: 2 }

// 2. Functional Update
store.set((s) => ({ a: s.a + 1 })); // { a: 11, b: 2 }

// 3. Full Replacement
store.set({ a: 0 }, true); // { a: 0 } (b is gone!)

subscribe()

Listen for state changes. Returns an unsubscribe function:

const unsub = counterStore.subscribe((state, prevState) => {
  console.log('Changed:', prevState.count, '→', state.count);
});

// Stop listening
unsub();

destroy()

Remove all listeners and reset state to the initial value:

counterStore.destroy();
// All listeners removed, state reset to initial