30-seconds-of-code/snippets/url-join.md

title, tags, cover, firstSeen, lastUpdated

title	tags	cover	firstSeen	lastUpdated
Join URL segments	string,regexp	digital-nomad-2	2018-01-16T15:53:03+02:00	2020-10-22T20:24:44+03:00

Joins all given URL segments together, then normalizes the resulting URL.

• Use Array.prototype.join() to combine URL segments.
• Use a series of String.prototype.replace() calls with various regular expressions to normalize the resulting URL (remove double slashes, add proper slashes for protocol, remove slashes before parameters, combine parameters with '&' and normalize first parameter delimiter).

const URLJoin = (...args) =>
  args
    .join('/')
    .replace(/[\/]+/g, '/')
    .replace(/^(.+):\//, '$1://')
    .replace(/^file:/, 'file:/')
    .replace(/\/(\?|&|#[^!])/g, '$1')
    .replace(/\?/g, '&')
    .replace('&', '?');

URLJoin('http://www.google.com', 'a', '/b/cd', '?foo=123', '?bar=foo');
// 'http://www.google.com/a/b/cd?foo=123&bar=foo'