title: React Javascript Array intrinsics
body: <p>I want to contain the Title array using the map function, but I get an error. How to modify the code?</p>
  <p>How do I fix the code to avoid the error? I m only doing this for today. I think I m really stupid</p>
  <p>First, get data from CartData.</p>
  <pre><code>const { data: CartData, error: CartError } = useSWR(http://localhost:3060/user/Carts, fetcher)
  </code></pre>
  <p>I tried console.log.</p>
  <p>console.log(CartData);</p>
  <pre><code>
  Object
  email: alstntorl@naver.com
  id: 1
  Cartd: Array(4)
  0: {id: 1, 
  Title: 나이키 x 앰부쉬 덩크  딥 로얄 블루, 
   …}
  1: {id: 11, 
  Title: 뉴발란스 2002R 그레이, 
   …}
  2: {id: 34, Title: 컨버스 하이크 하이 블랙 화이트 검,, …}
  3: {id: 36, Title: 아디다스 이지 부스트 380 미스트, 10, …}
  length: 4
  
  </code></pre>
  <p>I am trying to get Title information using the map function. But I get an error here.</p>
  <pre><code>
   const result = CartData.Cartd.map((list) =&gt; list.Title);
   console.log(result);
  
  </code></pre>
  <pre><code>
  Server Error
  TypeError: Cannot read property Cartd of undefined
  
  This error happened while generating the page. Any console logs will be displayed in the terminal window.
  Source
  .next\server\pages\mypage.js (32:28) @ mypage
  
    30 | 
    31 | 
  &gt; 32 |     const result = CartData.Cartd.map((list) =&gt; list.Title);
       |                            ^
    33 |     console.log(result);
    34 | 
    35 | 
  
  </code></pre>