What is Redux and how does it work? Redux क्या है और कैसे काम करता है?

// Redux: Predictable state container
// 1. Action - describes what happened
const INCREMENT = 'INCREMENT';
const action = { type: INCREMENT, payload: 1 };

// 2. Reducer - takes state and action, returns new state
function counterReducer(state = 0, action) {
  switch(action.type) {
    case INCREMENT:
      return state + action.payload;
    default:
      return state;
  }
}

// 3. Store - holds application state
import { createStore } from 'redux';
const store = createStore(counterReducer);

// 4. Dispatch - send action
store.dispatch({ type: INCREMENT, payload: 1 });

// 5. Subscribe - listen to changes
store.subscribe(() => {
  console.log(store.getState());
});