How to validate url?

Question

I want to validate urls. It should accept:

http://google.com

http://www.google.com

www.google.com

google.com

I refer Regex to match URL

Answer 1

This is a better way I think should be used to validate urls

reg = /https?:\/\/w{0,3}\w*?\.(\w*?\.)?\w{2,3}\S*|www\.(\w*?\.)?\w*?\.\w{2,3}\S*|(\w*?\.)?\w*?\.\w{2,3}[\/\?]\S*/
reg.test('www.google.com')    # will return true
reg.test('www.google')        # will return false

Let me know if you still not getting it correct.