Get protocol, domain, and port from URL

Why not use:

let full = window.location.origin

window.location.origin will be enough to get the same.

Here is the solution I'm using:

const result = `${ window.location.protocol }//${ window.location.host }`;

EDIT:

To add cross-browser compatibility, use the following:

const result = `${ window.location.protocol }//${ window.location.hostname + (window.location.port ? ':' + window.location.port: '') }`;

With ES6 template literals:

const url = `${location.protocol}//${location.hostname}${location.port?':'+location.port:''}`;

document.getElementById("result").innerText = url;

<div id="result"></div>

And you can simplify to:

const url = `${location.protocol}//${location.host}`;

document.getElementById("result").innerText = url;

<div id="result"></div>

Simple answer that works for all browsers:

let origin;

if (!window.location.origin) {
  origin = window.location.protocol + "//" + window.location.hostname + 
     (window.location.port ? ':' + window.location.port: '');
}

origin = window.location.origin;

ES6 style with configurable parameters.

/**
 * 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
}

window.location.protocol + '//' + window.location.host

console.log(`${req.protocol}://${req.get('host')}/${req.originalUrl}`);

• req.protocol - gives the protocol you used (e.g. HTTP)
• req.get(host) - gives the host name with the port number (e.g. localhost:8080)