【Element-UI】解決select 切換單選/多選 multiple 狀態 的問題

Codepen

https://codepen.io/braink-1400/pen/NWaayxm?editors=1111 

var Main = {
    data() {
      return {
        options: 
        [{
          value: '選項1',
          label: '黃金糕'
        }, {
          value: '選項2',
          label: '雙皮奶'
        }, {
          value: '選項3',
          label: '蚵仔煎'
        }, {
          value: '選項4',
          label: '龍須面'
        }, {
          value: '選項5',
          label: '北京烤鴨'
        }],
        value: '選項1',
        multiple:true,
      }
    },
    methods:{
      click(){
        if(this.multiple){
          this.value =[] ;
        }else{
          this.value ='' ;
        }
        setTimeout(()=>{
          this.value=[];
          this.multiple=!this.multiple
        });
      },
},
  }
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app');