check if string contains url anywhere in string using javascript

I want to check if string contains a url using javascript i got this code from google

        if(new RegExp("[a-zA-Z\d]+://(\w+:\w+@)?([a-zA-Z\d.-]+\.[A-Za-z]{2,4})(:\d+)?(/.*)?").test(status_text)) {
           alert("url inside");
         }
 

But this one works only for the url like "http://www.google.com" and "http://google.com" but it doesnt work for "www.google.com" .Also i want to extract that url from string so i can process that url.

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