[Redux] Implementing combineReducers() from Scratch

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

The combineReducers function we used in previous post:

const todoApp = combineReducers({

  todos,

  visibilityFilter

});

It accepts and object as agruement;
It returns an function

Implemente by ourself:

 // reducers: {todos: todos, filter: filter}

const combineReducers = (reducers) => {

   // return a reducer function

  return (state={},action)=>{

     // combine the reducers

    return Object.keys(reducers)

      .reduce( (acc, curr)=>{

        acc[curr] = reducers[curr](

          state[curr],

          action

        ); // todos: todos

      return acc;

    }, {})

  }

};