Previous, we do composition with objects:
const todoApp = (state = {}, action) => {
return {
todos: todos(
state.todos,
action
),
visibilityFilter: visibilityFilter(
state.visibilityFilter,
action
)
};
};
Since it is common options in Redux, there is a function call ‘combineReducers‘:
const {combineReducers} = Redux;
combineReducers({
todos, //ES6 shortcut syntax
visibilityFilter
});
[Redux] Reducer Composition with combineReducers()
原文：http://www.cnblogs.com/Answer1215/p/5065436.html