七、数据持久化

function getCity(){
   let defaultCity = "天门";
   if(localStorage.getItem("city")){
     defaultCity = localStorage.getItem("city")
   }
   return defaultCity;
}
export default new Vuex.Store({
  state: {
    city:getCity()
  },
  mutations: {
    changeCity(state,city){
      state.city = city;
    }
  },
  actions: {
    changeCity(ctx,city){
      ctx.commit("changeCity",city)
        //1.设置缓存
      localStorage.setItem("city",city)
    }
  }
})