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React Native Academy · Aula

Criando um armazenamento Zustand

Instale o Zustand, defina um armazenamento com create, adicione propriedades de estado e funções de ação e entenda como o armazenamento difere da arquitetura Redux.

Criando um armazenamento Zustand é uma aula grátis de React Native Academy no CoddyKit. Esta é a aula 1 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de React Native Academy, e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de React Native Academy inclui 4 aulas no total.

Partes desta aula ainda não foram traduzidas e aparecem em inglês.

What Is Zustand?

Zustand (German for 'state') is a minimal, fast state management library for React. Unlike Redux, it requires no boilerplate like action creators, reducers, or a Provider wrapper. You define a store as a single function, and any component can subscribe to it with a simple hook. It is ideal for apps that need global state without the complexity of Redux Toolkit.

Installing Zustand

Install Zustand from npm with a single command. It has zero dependencies and is compatible with React Native out of the box. The package is lightweight — under 1 kB gzipped — which keeps your app's bundle size small.

npm install zustand

Creating Your First Store

Call create from Zustand and pass it a function that receives set and returns an object containing your state properties and actions. The returned value is a custom hook — conventionally named useXxxStore — that components call to access the store.

import { create } from 'zustand';

interface CounterStore {
  count: number;
  increment: () => void;
  decrement: () => void;
  reset: () => void;
}

export const useCounterStore = create<CounterStore>((set) => ({
  count: 0,
  increment: () => set((state) => ({ count: state.count + 1 })),
  decrement: () => set((state) => ({ count: state.count - 1 })),
  reset: () => set({ count: 0 }),
}));

The set Function

The set function is how Zustand updates state. You can pass it either a partial state object (Zustand merges it with existing state) or a callback that receives the current state and returns the updated portion. Zustand automatically notifies all subscribers when state changes.

// Partial object — Zustand merges it
set({ count: 0 });

// Callback — use when new value depends on previous value
set((state) => ({ count: state.count + 1 }));

// Replace entire state (pass true as second arg)
set(() => ({ count: 0, name: 'reset' }), true);

No Provider Needed

One of Zustand's biggest advantages over Redux is that you do not need to wrap your component tree in a Provider. The store lives outside React and components subscribe to it directly via the returned hook. This means you can use the store anywhere — in components, in callbacks, or even outside React components.

// No Provider needed — just use the hook anywhere
function CounterDisplay() {
  const count = useCounterStore((state) => state.count);
  return <Text>Count: {count}</Text>;
}

function CounterButtons() {
  const increment = useCounterStore((state) => state.increment);
  const decrement = useCounterStore((state) => state.decrement);
  return (
    <View>
      <Button title='+' onPress={increment} />
      <Button title='-' onPress={decrement} />
    </View>
  );
}

Subscribing to Specific State

Pass a selector function to the store hook to subscribe to only part of the state. The component re-renders only when the selected value changes. Without a selector, the component re-renders whenever any part of the store updates, which can hurt performance in large stores.

// Only re-renders when count changes
const count = useCounterStore((state) => state.count);

// Only re-renders when user.name changes
const username = useUserStore((state) => state.user.name);

// Without selector — re-renders on ANY store change (avoid this)
const everything = useCounterStore();

Accessing the Store Outside React

Zustand stores expose a getState() method that reads the current state synchronously without hooks. There is also a subscribe() method for non-React subscriptions and a setState() method for imperative updates. This is useful in utility functions, API interceptors, or navigation helpers that run outside React component lifecycle.

// Access store state anywhere — no hooks required
import { useCounterStore } from './counterStore';

// Read state outside React
const currentCount = useCounterStore.getState().count;

// Update state outside React
useCounterStore.getState().increment();

// Subscribe outside React
const unsub = useCounterStore.subscribe((state) => {
  console.log('Count changed to:', state.count);
});

Async Actions in Zustand

Zustand actions can be async — just mark the function async and call set after the await. You do not need special async utilities like Redux's createAsyncThunk. You can add loading and error state directly to the store and update them inside the async action.

export const usePostsStore = create<PostsStore>((set) => ({
  posts: [],
  loading: false,
  error: null,
  fetchPosts: async () => {
    set({ loading: true, error: null });
    try {
      const res = await fetch('https://api.example.com/posts');
      const data = await res.json();
      set({ posts: data, loading: false });
    } catch (e) {
      set({ error: 'Failed to load', loading: false });
    }
  },
}));

Comparing Zustand and Redux

Redux Toolkit is more structured and provides stronger conventions for large teams, time-travel debugging, and complex state. Zustand excels when you need global state with minimal ceremony — a single file, no action types, no Provider. Both are valid choices; pick Zustand for small-to-medium apps or when you want to move fast without Redux boilerplate.

Organizing Multiple Stores

In larger apps, split your state into multiple focused stores rather than one massive store. For example, create useAuthStore, useCartStore, and useSettingsStore separately. Each store file is small, independently testable, and imported only by the components that need it. This prevents unrelated state changes from triggering unnecessary re-renders.

// stores/authStore.ts
export const useAuthStore = create<AuthStore>((set) => ({ /* ... */ }));

// stores/cartStore.ts
export const useCartStore = create<CartStore>((set) => ({ /* ... */ }));

// Component imports only what it needs
import { useAuthStore } from '../stores/authStore';
import { useCartStore } from '../stores/cartStore';

Immer Middleware for Complex Updates

If your state is deeply nested and you want mutating-style updates (like Redux Toolkit's Immer integration), wrap the store creator with Zustand's immer middleware. With Immer, you can write state.user.preferences.theme = 'dark' instead of spreading every level of the object manually.

import { create } from 'zustand';
import { immer } from 'zustand/middleware/immer';

export const useSettingsStore = create(immer<SettingsStore>((set) => ({
  user: { name: '', preferences: { theme: 'light', notifications: true } },
  setTheme: (theme) => set((state) => {
    state.user.preferences.theme = theme; // Immer makes this safe
  }),
})));

Quick Check

Test your understanding of React Native Mobile Development concepts from this lesson.

Lesson Recap

In this lesson you learned: Zustand creates global stores with minimal boilerplate using a single create call, no Provider is required because the store lives outside the React tree, and async actions work natively by marking store functions as async. Next up we explore reading and updating Zustand store state in components.

Perguntas Frequentes

A aula “Criando um armazenamento Zustand” é grátis?

Sim — o texto completo de “Criando um armazenamento Zustand” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de React Native Academy, atualize para CoddyKit PRO. O curso de React Native Academy inclui 4 aulas no total.

O que vou aprender em “Criando um armazenamento Zustand”?

Instale o Zustand, defina um armazenamento com create, adicione propriedades de estado e funções de ação e entenda como o armazenamento difere da arquitetura Redux. Você pratica React Native Academy com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.

Preciso ter experiência prévia para começar React Native Academy?

Nenhuma experiência prévia é necessária. React Native Academy no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 1 de 4.

Quanto tempo leva a aula “Criando um armazenamento Zustand”?

A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.

Posso escrever e executar código nesta aula de React Native Academy?

Sim. Cada aula de React Native Academy inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.

Todas as aulas deste curso

  1. Criando um armazenamento Zustand
  2. Lendo e atualizando o estado do armazenamento em componentes
  3. Persistindo o estado do Zustand com AsyncStorage
  4. Padrão de fatias e integração com DevTools
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