初入Redux 实现combineReducers函数（五）

      const combineReducers=(reducers)=>{
        console.log('旧的reducers')
        console.log(reducers)
        console.log('旧的reducers')


        //注意reducer是一个函数,所以我们返回一个函数
        return (state=[],action)=>{

          //返回一个新的状态对象
          let newReducer=Object.keys(reducers).reduce(
            (nextState,key)=>{
              //根据key取出函数
              let subReducer=reducers[key]

              //调用该函数
              let subState=subReducer(state[key],action)

              //赋值给新的对象
              nextState[key]=subState
            return nextState
            },{}//一个新的空对象
          )
          console.log('新的Reducer')
          console.log(newReducer)
          console.log('新的Reducer')
          return  newReducer
        }

      }

本章请参考源码以便更好的理解Redux

    这是最终的打印。