JSFiddle - React, Tailwind, and code Playground

JavaScript

//Play with the sting prototype
String.prototype.getFirstFolder = function ()
{ //Get First Folder
    var parts = this.split('/');
    var ret = parts[0];//if parts.length is <=1 then its an invalid url
    var stop = Math.min(4,parts.length);
    for(i=1;i<stop;i++) {
        ret += "/" + parts[i];
    }
    return ret;
}
    
alert(   "http://www.google.com/test/pages.html".getFirstFolder() );

alert(   "http://".getFirstFolder() );

alert(   "http://www.google.com/test/anotherfolder/pages.html".getFirstFolder() );