xxxxxxxxxx<html><head><meta charset="utf-8"><title>W3Cschool教程(w3cschool.cn)</title></head><body><p> typeof 操作符返回变量、对象、函数、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>