Ruby Regex to extract domain from email address

Question

I have no real previous experience using regex, just saying. I want to extract domain names from email addresses with the below format.

richardc@mydomain.com so that the regex returns just: mydomain

With an explanation of how/why it works if possible! Cheers

Answer 1

Here capturing (...) the domain name in group \1 and replace the whole string with that capture, which yields the domain name only at the end.

email = 'richardc@mydomain.com'
domain = email.gsub(/.+@([^.]+).+/, '\1')
# => mydomain

.+ means any character(except \n). So its basically matching the whole email string, and capturing the domain name using ([^.]+) [means anything but dot]