Window.location.origin就足以得到相同的。

首先获取当前地址

var url = window.location.href

然后解析这个字符串

var arr = url.split("/");

你的网址是:

var result = arr[0] + "//" + arr[2]

ES6风格，具有可配置参数。

/**
 * Get the current URL from `window` context object.
 * Will return the fully qualified URL if neccessary:
 *   getCurrentBaseURL(true, false) // `http://localhost/` - `https://localhost:3000/`
 *   getCurrentBaseURL(true, true) // `http://www.example.com` - `https://www.example.com:8080`
 *   getCurrentBaseURL(false, true) // `www.example.com` - `localhost:3000`
 *
 * @param {boolean} [includeProtocol=true]
 * @param {boolean} [removeTrailingSlash=false]
 * @returns {string} The current base URL.
 */
export const getCurrentBaseURL = (includeProtocol = true, removeTrailingSlash = false) => {
  if (!window || !window.location || !window.location.hostname || !window.location.protocol) {
    console.error(
      `The getCurrentBaseURL function must be called from a context in which window object exists. Yet, window is ${window}`,
      [window, window.location, window.location.hostname, window.location.protocol],
    )
    throw new TypeError('Whole or part of window is not defined.')
  }

  const URL = `${includeProtocol ? `${window.location.protocol}//` : ''}${window.location.hostname}${
    window.location.port ? `:${window.location.port}` : ''
  }${removeTrailingSlash ? '' : '/'}`

  // console.log(`The URL is ${URL}`)

  return URL
}

尝试使用正则表达式(Regex)，当你想要验证/提取东西或甚至用javascript做一些简单的解析时，它将非常有用。

正则表达式是:

/([a-zA-Z]+):\/\/([\-\w\.]+)(?:\:(\d{0,5}))?/

演示:

function breakURL(url){

     matches = /([a-zA-Z]+):\/\/([\-\w\.]+)(?:\:(\d{0,5}))?/.exec(url);

     foo = new Array();

     if(matches){
          for( i = 1; i < matches.length ; i++){ foo.push(matches[i]); }
     }

     return foo
}

url = "https://www.google.co.uk:55699/search?q=http%3A%2F%2F&oq=http%3A%2F%2F&aqs=chrome..69i57j69i60l3j69i65l2.2342j0j4&sourceid=chrome&ie=UTF-8"


breakURL(url);       // [https, www.google.co.uk, 55699] 
breakURL();          // []
breakURL("asf");     // []
breakURL("asd://");  // []
breakURL("asd://a"); // [asd, a, undefined]

现在你也可以进行验证了。

实际上，window.location.origin在遵循标准的浏览器中工作得很好，但你猜怎么着。IE没有遵循标准。

正因为如此，我在IE、FireFox和Chrome浏览器中使用了这个方法:

var full = location.protocol+'//'+location.hostname+(location.port ? ':'+location.port: '');

但为了将来可能引起冲突的增强，我在“location”对象之前指定了“window”引用。

var full = window.location.protocol+'//'+window.location.hostname+(window.location.port ? ':'+window.location.port: '');

var getBasePath = function(url) {
    var r = ('' + url).match(/^(https?:)?\/\/[^/]+/i);
    return r ? r[0] : '';
};