re = /^https:\/\/(youtu\.be\/[A-Za-z0-9]{11}|www\.youtube\.com\/watch\?v=[A-Za-z0-9]{11})$/
str = ''
# Print the match result
str.match(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html