javascript - How to find if a text contains url string

itemprop="text">

How can I find if text contains a url
string. I mean if I
have

Sometexthttp://daasddas
            some text

I want
rel="nofollow">http://daasddas to be achored or maked as a
link wit javascript

itemprop="text">

class="normal">Answer

 function
            replaceURLWithHTMLLinks(text)
 {
 var exp =
            /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;

            return text.replace(exp,"$1"); 


            }