JSFiddle - React, Tailwind, and code Playground

JavaScript

var a = 'http://www.youtube.com/somevideo/vimeo';
var b = 'http://vimeo.com/somevideo/youtube';

var test = checkUrl(b);
console.log(test); //prints Vimeo


function checkUrl(test_url) {
    var testLoc = document.createElement('a');
        testLoc.href = test_url.toLowerCase();
    url = testLoc.hostname;
    var what;
    if (url.indexOf('youtube.com') !== -1) {
        what='Youtube';
    }else if (url.indexOf('vimeo.com') !== -1) {
        what='Vimeo';
    }else{
        what='None';
    }
    return what;
}