Mastering JavaScript Functional Programming - Second Edition

A React-Redux reducer

We can see another example that involves assigning functions. As we mentioned earlier in this chapter, React-Redux works by dispatching actions that are processed by a reducer. Usually, the reducer includes code with a switch:

function doAction(state = initialState, action) {  let newState = {};  switch (action.type) {    case "CREATE":      // update state, generating newState,      // depending on the action data      // to create a new item      return newState;    case "DELETE":      // update state, generating newState,      // after deleting an item      return newState;    case "UPDATE":      // update an item,      // and generate an updated state      return newState;    default:      return state;  }}

Providing initialState as a default value for state is a simple way of initializing ...