Get domain name

getDomainName.js

function getDomainName(url){
  function isDomainName(domain){
    return domain.match(/^[a-zA-Z0-9][a-zA-Z0-9-\.]{1,61}[a-zA-Z0-9]\.[a-zA-Z]{2,}$/)!==null
  }

  let matches = url.match(/^(?:https?:\/\/)?(?:[^@\/\n]+@)?(?:www\.)?([^:\/\n]+)/)

  if(matches.length>=2){
    let domain = matches[1]
    return isDomainName(domain)? domain : null
  }
  return null
}