Closure Example Actual

sample_node.js

const getInfoFromURL = path => {
   const URL = require(“url”).URL;
   const myUrl = new URL(path)
   const pathname = myUrl.pathname
   
   const getUsernameFromURL = pathname => {
      const regex = new RegExp(‘/@’);
      const username = pathname.split(regex).slice(1)[0]
      if(!username) {
        return “Error in parsing: URL needs to be in format://hostname:port/@username”
      }
      return username
    }
   
    const getPathnameFromURL = pathname => {
       const regex = new RegExp(‘/’);
       const name = pathname.split(regex).slice(1)[0]
       if(!name) {
          return “Error in parsing: URL needs to be in format://hostname:port/pathname”
       }
      return name
     }
    
    return (param) => {
       if (param === “username”) return getUsernameFromURL(pathname)
       else if (param === “pathname”) return getPathnameFromURL(pathname)
       else return “error”
    }
}

// You should get “xiaoyunyang”
getInfoFromURL(“https://medium.com/@xiaoyunyang")("username")
               
// You should get “@xiaoyunyang
getInfoFromURL(path)(“pathname”)