### 1.淺拷貝（只拷貝地址）  - 此時改變棧中的任一對象的值，倆者的值都會改變，因為他們的存儲地址一樣 - 改變復制的對象，原對象也會改變 ``` <script> var obj = { name: "chengchao", age: "20" } cheng = obj cheng.name = "zhang" console.log(cheng, obj) //{name: "zhang", age: "20"} {name: "zhang", age: "20"} </script> ``` ### 2.深拷貝（拷貝值和址）將值放入另一個地址中  - 此時對象之間屬性的改變互不影響 - 改變復制的對象，原對象值不會改變 ``` <script> var obj = { name: "chengchao", age: "20" } cheng = { ...obj } cheng.name = "zhang" console.log(cheng, obj) //{name: "zhang", age: "20"} {name: "chengchao", age: "20"} </script> ``` ## promise解決回調地獄 ``` <script> function getData(url){ const promise = new Promise((resolve,reject)=>{ $.ajax({ url, dataType:"jsonp", success:res=>{ resolve(res) }, error:err=>{ reject(err); } }) }) return promise; } getData("https://api.douban.com/v2/book/search?q=javascript&count=1").then(res=>{ let id = res.books[0].id; return getData(`https://douban.uieee.com/v2/book/${id}`) }).then(res=>{ console.log(res); }) </script> ```