What is State Management?
State management refers to the patterns and tools used to manage data within applications. Effective state management ensures predictable data flow, improves maintainability, and scales with application complexity.
Local vs Global State
State Stores
Reactivity Systems
Core Concepts
Local vs Global State
Local state is component-specific while global state persists across components. Proper scoping reduces unnecessary re-renders and improves performance.
// Local state example
const [count, setCount] = useState(0);
// Global state example
const user = useGlobalStore(state => state.user);State Containment Patterns
Use parent-child communication with context providers, state containers, or event emitters for consistent state flow.
Lifted State
Move shared state to a common ancestor component.
Centralized Store
Use libraries like Redux or Zustand for global state management.
Framework Implementation
React Context API
Create context providers for component trees with useContext hook for consuming values.
const UserContext = createContext();
const UserProvider = ({ children }) => {
const [user, setUser] = useState(null);
return (
{children}
);
};Vue 3 Composition API
Use reactive() and ref() for fine-grained state management with computed hooks and watchers.
import { reactive, computed } from 'vue';
const state = reactive({
count: 0
});
const doubleCount = computed(() => state.count * 2);State Best Practices
Normalize Data
Store related data in a single source of truth to avoid inconsistencies.
Immutable Updates
Use immutability for predictable state transitions and debugging.
Minimal State
Derive non-essential data from computed properties instead of storing it directly.
State Diagram
Component -> [Local State] -> Prop Drilling -> Child Components <->
Global Store
Advanced Techniques
State Hydration
Efficiently synchronize client/server state in SSR applications.
Time Travel
Implement state history with middleware for debugging and user undo capabilities.
Persistent State
Store UI preferences using localStorage while maintaining security boundaries.