設置緩存，將JSON數據寫進緩存要先轉化為string類型 ``` localStorage.setItem('bannerList', JSON.stringify(tempList)); ``` 讀取緩存，將緩存中的string類型讀取出來后可以轉化為JSON類型 ``` var bannerList = JSON.parse(localStorage.getItem('bannerList')) ``` ``` var bannerList = JSON.parse(localStorage.getItem('bannerList')) if(bannerList) { //如果緩存存在，則直接獲取數據 this.bannerList = bannerList; }else { //不存在則發送ajax請求 moviemodel.getInTheaters().then(res=>{ let tempList = []; res.body.subjects.slice(0, 3).forEach(ele => { tempList.push(ele.images.small) }); this.bannerList = tempList; //將bannerList轉化為字符串類型存入緩存 localStorage.setItem('bannerList', JSON.stringify(tempList)); }) } ```