typeof(undefined) == undefined 成立吗?_typeof (undefined) 结果为undefined-CSDN博客

网站介绍:1、问题:在Javascript中,typeof(undefined) == undefined成立吗?答案:不成立,全局函数 typeof()返回值类型为字符串类型,六个可能值: "number", "string", "boolean", "object" ,"function", 和 "undefined"。只有typeof(undefined) =="undefined";..._typeof (undefined) 结果为undefined