Need assistance with regex in javascript

Question

I would like to validate url's in javascript before user proceeds further.

The urls below should match;

• http://google.com
• http://www.google.com
• www.google.com
• google.com

And not match;

• http://google
• http://www.google
• www.google
• google

Please help me im really bad at regex

Answer 1

try like this

     var urlR = /^(?:([A-Za-z]+):)?(\/{0,3})([0-9.\-A-Za-z]+)
       (?::(\d+))?(?:\/([^?#]*))?(?:\?([^#]*))?(?:#(.*))?$/;
     var url= content.match(urlR);

or

  var regex = new RegExp("^(http[s]?:\\/\\/(www\\.)?|ftp:\\/\\/(www\\.)?|www\\.){1}([0-9A-Za-z-\\.@:%_\+~#=]+)+((\\.[a-zA-Z]{2,3})+)(/(.)*)?(\\?(.)*)?");

     if(regex.test("http://google.com")){
      alert("Successful match");
    }else{
    alert("No match");
      }