re = /([2-9]\d{2})(?!1)(?<!1)/m
str = '123
456
789
211
333
111
222
411
511
123456789
1234-1234-12345
555-444-333
555-411-311
These would be valid area codes: 414, 608, 920, 319, 715
These would NOT be valid: 023, 123, 411, 611, 811, 911'
# Print the match result
str.scan(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