redux

不可以这么写,因为这样把原来的state给改了。

return一个javascript object

const redux = require('redux');
const createStore = redux.createStore;


const initialState = {
        counter:0,

}
//Reducer
const rootReducer = (state=initialState, action) =>{
        if(action.type==='INC_COUNTER'){
                return{
                        ...state,
                        counter:state.counter+1
                }
        }
        if(action.type==='ADD_COUNTER'){
                return{
                        ...state,
                        counter:state.counter+action.value
                }
        }
        
        return state;
};

//Store
const store = createStore(rootReducer);
console.log(store.getState());

//dispatch
store.dispatch({type: 'INC_COUNTER'});//里面是一个action 并且应该是一个javascript object type property全大写
store.dispatch({type: 'ADD_COUNTER', value:10}); //所以dispatch 可以很多个 很多action 最后reducer执行
console.log(store.getState());