js引入path模块：
const path = require('path')
path.parse序列化路径 返回一个对象
const path = require('path')
console.log(__filename) //获取本js路径
//序列化路径 返回一个对象
console.log(path.parse(__filename))
如图所示：
path.extname查看文件的后缀名
console.log(path.extname(__filename)) //.js
path.basename返回此文件的全称
console.log(path.basename(__filename)); //path.js
path.dirname返回此文件所在的文件夹路径
console.log(path.dirname(__filename)) //C:\Users\mi\Desktop\day02
path.join路径拼接
console.log(path.join(path.dirname(__filename),'abc','def'))
//C:\Users\mi\Desktop\day02\abc\def
