JavaScript 变量声明

<html>
   <head>
      <title>JavaScript Numbers</title>
   </head>

   <body>
      <script>
         var num = 10.2;
         if (num == Math.floor(num)) {
            alert("Whole Number")
         } else {
            alert("Decimal Number")
         }
      </script>
   </body>
</html>