js 简单闭包 

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div class="title"></div>
  <button class="add">add</button>
  <script>
    let x = printTitle()
    x()
    document.querySelector('.add').addEventListener('click', x)
    function printTitle() {
      let text = 0
      return () => {
        document.querySelector('.title').textContent = text++
      }
    }
  </script>
</body>

</html>
posted @ 2020-12-01 09:51  EvilChan  阅读(53)  评论(0)    收藏  举报