源代码
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>享学课堂</title> </head> <body> <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>
运行结果