Javascript函数内如果不写return,那么返回值是undefined

示例:下面的函数没有return语句,那么该函数的返回值是undefined:

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

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    function fn() {

    }
    let re = fn()
    console.log(re)
  </script>
</body>

</html>

控制台输出:
在这里插入图片描述

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