Clean up user-entered phone numbers so that they can be sent SMS messages.
The North American Numbering Plan (NANP) is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code:
NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as area code, followed by a seven-digit local number. The first three digits of the local number represent the exchange code, followed by the unique four-digit number which is the subscriber number.
The format is usually represented as
N is any digit from 2 through 9 and
X is any digit from 0 through 9.
Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code (1) if present.
For example, the inputs
1 613 995 0253
should all produce the output
Note: As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.
For installation and learning resources, refer to the exercism help page.
For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:
gem install minitest
If you would like color output, you can
require 'minitest/pride' in
the test file, or note the alternative instruction, below, for running
the test file.
Run the tests from the exercise directory using the following command:
To include color from the command line:
ruby -r minitest/pride phone_number_test.rb
Event Manager by JumpstartLab http://tutorials.jumpstartlab.com/projects/eventmanager.html
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
require 'minitest/autorun' require_relative 'phone_number' # Common test data version: 1.2.0 39cba0d class PhoneNumberTest < Minitest::Test def test_cleans_the_number # skip assert_equal "2234567890", PhoneNumber.clean("(223) 456-7890") end def test_cleans_numbers_with_dots skip assert_equal "2234567890", PhoneNumber.clean("223.456.7890") end def test_cleans_numbers_with_multiple_spaces skip assert_equal "2234567890", PhoneNumber.clean("223 456 7890 ") end def test_invalid_when_9_digits skip assert_nil PhoneNumber.clean("123456789") end def test_invalid_when_11_digits_does_not_start_with_a_1 skip assert_nil PhoneNumber.clean("22234567890") end def test_valid_when_11_digits_and_starting_with_1 skip assert_equal "2234567890", PhoneNumber.clean("12234567890") end def test_valid_when_11_digits_and_starting_with_1_even_with_punctuation skip assert_equal "2234567890", PhoneNumber.clean("+1 (223) 456-7890") end def test_invalid_when_more_than_11_digits skip assert_nil PhoneNumber.clean("321234567890") end def test_invalid_with_letters skip assert_nil PhoneNumber.clean("123-abc-7890") end def test_invalid_with_punctuations skip assert_nil PhoneNumber.clean("123-@:!-7890") end def test_invalid_if_area_code_does_not_start_with_2_9 skip assert_nil PhoneNumber.clean("(123) 456-7890") end def test_invalid_if_exchange_code_does_not_start_with_2_9 skip assert_nil PhoneNumber.clean("(223) 056-7890") end # Problems in exercism evolve over time, as we find better ways to ask # questions. # The version number refers to the version of the problem you solved, # not your solution. # # Define a constant named VERSION inside of the top level BookKeeping # module, which may be placed near the end of your file. # # In your file, it will look like this: # # module BookKeeping # VERSION = 1 # Where the version number matches the one in the test. # end # # If you are curious, read more about constants on RubyDoc: # http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html def test_bookkeeping skip assert_equal 2, BookKeeping::VERSION end end
# Phone Number class PhoneNumber INVALID = ('0' * 10).freeze attr_reader :input def initialize(input) @input = input end def number return INVALID unless valid? return stripped if valid_ten_digits? stripped[1..-1] if valid_eleven_digits? end def area_code number[0..2] end def to_s '(' + number[0..2] + ') ' + number[3..5] + '-' + number[6..9] end private def valid? no_letters? && (valid_ten_digits? || valid_eleven_digits?) end def valid_ten_digits? stripped.size == 10 end def valid_eleven_digits? stripped.size == 11 && stripped.chars.first == '1' end def stripped input.gsub(/\D/, '') end def no_letters? !input.match(/[a-zA-Z]/) end end
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.