Get protocol, domain, and port from URL

const full = location.protocol + '//' + location.host;

None of these answers seem to completely address the question, which calls for an arbitrary url, not specifically the url of the current page.

Method 1: Use the URL API (caveat: no IE11 support)

You can use the URL API (not supported by IE11, but available everywhere else).

This also makes it easy to access search params. Another bonus: it can be used in a Web Worker since it doesn't depend on the DOM.

const url = new URL('http://example.com:12345/blog/foo/bar?startIndex=1&pageSize=10');

Method 2 (old way): Use the browser's built-in parser in the DOM

Use this if you need this to work on older browsers as well.

//  Create an anchor element (note: no need to append this element to the document)const url = document.createElement('a');//  Set href to any pathurl.setAttribute('href', 'http://example.com:12345/blog/foo/bar?startIndex=1&pageSize=10');

That's it!

The browser's built-in parser has already done its job. Now you can just grab the parts you need (note that this works for both methods above):

//  Get any piece of the url you're interested inurl.hostname;  //  'example.com'url.port;      //  12345url.search;    //  '?startIndex=1&pageSize=10'url.pathname;  //  '/blog/foo/bar'url.protocol;  //  'http:'

Bonus: Search params

Chances are you'll probably want to break apart the search url params as well, since '?startIndex=1&pageSize=10' isn't too useable on its own.

If you used Method 1 (URL API) above, you simply use the searchParams getters:

url.searchParams.get('startIndex');  // '1'

Or to get all parameters:

function searchParamsToObj(searchParams) {  const paramsMap = Array    .from(url.searchParams)    .reduce((params, [key, val]) => params.set(key, val), new Map());  return Object.fromEntries(paramsMap);}searchParamsToObj(url.searchParams);// -> { startIndex: '1', pageSize: '10' }

If you used Method 2 (the old way), you can use something like this:

// Simple object output (note: does NOT preserve duplicate keys).var params = url.search.substr(1); // remove '?' prefixparams    .split('&')    .reduce((accum, keyval) => {        const [key, val] = keyval.split('=');        accum[key] = val;        return accum;    }, {});// -> { startIndex: '1', pageSize: '10' }

first get the current address

var url = window.location.href

Then just parse that string

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

your url is:

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

Hope this helps