html运行实例（eg_js_type_convert_typeof

代码示例：（标识：eg_js_type_convert_typeof_all）

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript typeof 运算符</h2>

<p>typeof 运算符返回变量、对象、函数或表达式的类型。</p>

<p id="demo"></p>

<script>
document.getElementById("demo").innerHTML = 
  typeof "john" + "<br>" +
  typeof 3.14 + "<br>" +
  typeof NaN + "<br>" +
  typeof false + "<br>" +
  typeof [1,2,3,4] + "<br>" +
  typeof {name:'john', age:34} + "<br>" +
  typeof new Date() + "<br>" +
  typeof function () {} + "<br>" +
  typeof myCar + "<br>" +
  typeof null;
</script>

</body>
</html>