I am, again.
The only way to modify the state is through emitting an action, which is an object that describes what should change. Action Creators are the functions that are dispatched to emit a …
Reducers are “pure functions”. They should not have any side-effects nor mutate the state — they must return a modified copy.
Each reducer takes 2 parameters: the previous state (state) and an action object. We can also use an ES6 feature called default parameters to set the default initial state.