url关键字匹配（JavaScript）

Description:

Write a function that when given a URL as a string, parses out just the domain name and returns it as a string.

For example:

console.log(domainName("http://github.com/carbonfive/raygun"));  //"github" 
console.log(domainName("http://www.zombie-bites.com"));  //"zombie-bites"
console.log(domainName("https://www.cnet.com"));   // "cnet"
console.log(domainName('mailto:user@foo.example''));  // "foo"

使用正则解决该问题比较方便

• my answer

function domainName(url){
    if (/www\./.test(url) == true) {
      url.match(/www\.([\w\-]+)/);
      return RegExp.$1;
    } else if (/\/\//.test(url) == true) {
      url.match(/\/\/([\w\-]+)/);
      return RegExp.$1;
    } else {
      url.match(/([\w\-]+)\./);
      return RegExp.$1;
    }
}

• best answer

function domainName(url){
  url = url.replace("https://", '');
  url = url.replace("http://", '');
  url = url.replace("www.", '');
  return url.split('.')[0];
};