前端常见面试题（六）原型链

它们的_proto_都指向了Object.prototype。js原型链最终指向的是Object原型对象，Object原型对象指向null.

https://www.cnblogs.com/catherLee/p/13287710.html

https://www.liaoxuefeng.com/wiki/1022910821149312/1023022043494624

https://juejin.im/post/5d713de26fb9a06ad3474c15