JSFiddle - React, Tailwind, and code Playground

JavaScript

var twit = "hello @nilambar, I am #testing #hashtag @jhilke and http://www.nilambar.net this URL!";
function parseTwit(str)
{
    //parse URL
    str = str.replace(/[A-Za-z]+:\/\/[A-Za-z0-9-_]+\.[A-Za-z0-9-_:%&~\?\/.=]+/g,function(s){        
        return s.link(s);
    });
    //parse user_name
    str = str.replace(/[@]+[A-Za-z0-9_]+/g,function(s){
        var user_name = s.replace('@','');
        return s.link("http://twitter.com/"+user_name);
    });
    //parse hashtag
    str = str.replace(/[#]+[A-Za-z0-9_]+/g,function(s){
        var hashtag = s.replace('#','');
        return s.link("http://search.twitter.com/search?q="+hashtag);
    });    
    return str;
}
document.write(parseTwit(twit));