如何通过参数获取Object的子节点？

Question

代码如下：let china = {    zhejiang: {        hangzhou: 'xihu'    }}// xihuconsole.log(china.zhejiang.hangzhou)// xihuconsole.log(china['zhejiang']['hangzhou'])// 能否通过 key 来访问 china 使之能输出 xihuconsole.log( china[key] )