显示所有变量的类型
- <!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>