Read Store's Initial State in Redux Reducer

Question

Initial state in a Redux app can be set in two ways:

• pass it as the second argument to createStore (docs link)
• pass it as the first argum

Answer 1

how do you read that state from the store and make it the first argument in your reducers?

combineReducers() do the job for you. The first way to write it is not really helpfull :

const rootReducer = combineReducers({ todos, users })

But the other one, that is equivalent is more clear :

function rootReducer(state, action) {
   todos: todos(state.todos, action),
   users: users(state.users, action)
}