If we think about this in terms of React, we're probably not expecting that our components call store.getState() all the time. Rather, we would think that our store would know that its state has changed and pass different props to the components.

That's a good thought acutally. In the last section, we noticed that the store has a subscribe method. This method takes a function dictates what should happen whenever the state in the store is updated.

subscribe also returns a function that you can call to unsubscribe.

const subscriber = () => console.log('Subscriber!' store.getState().value);

const unsubscribe = store.subscribe(subscriber);

store.dispatch(increment()); // "Subscriber! 1"
store.dispatch(add(4)); // "Subscriber! 5"

unsubscribe();

store.dispatch(add(1000)); // (Silence)

Now, it's silent, but the action was still dispatched and the reducer still updated the state. We just turned off our notifcations.