How to detect if URL() constructor is supported by browsers?

Question

I want to detect if a browser support the URL() constructor.

I want to use it like this:

const url = new URL(urlString, [baseURLstring])

I can't find a proper method to check if it's supported by browser?

Answer 1

Assuming the check needs to be done in JavaScript -

Use if(typeof URL === "function")

If true URL is supported

Sample Code

if (typeof URL === "function") {
  const baseURLstring = "http://www.aaa.bbb/";
  let urlString = "/hello";
  const url = new URL(urlString, [baseURLstring]);
  console.log(url)
}
else if (navigator.userAgent.indexOf('MSIE') != -1 && typeof URL === 'object') {
  const baseURLstring = "http://www.aaa.bbb/";
  let urlString = "/hello";
  const url = new URL(urlString, [baseURLstring]);
  console.log(url)
}

Answer 2

1. If const is supported, URL is likely also supported - except
2. URL is not supported by IE at all it seems
   • https://developer.mozilla.org/en-US/docs/Web/API/URL/URL
   • http://caniuse.com/#feat=url
3. if (window.URL) ...