Convert all occurrence of www in string with http://www I have tried 
Regular expression: /^www(?!http\:\/\/|https\:\/\/)./g; but it's working only in case when any character or digit don't precede www. For example: Find me at www.test.com in this case it's failing but it's working for www.google.com find me on this. I don't know how to put condition in regular exp for this. 
function mailify(text)
{
  var regEx = /^www(?!http\:\/\/|https\:\/\/)/g;
  return text.replace(regEx, "http://www");
}
console.log(mailify("www.ni@gmail.com"));
 
     
     
     
     
     
    
 
    