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lujanfernaud's solution

to Phone Number in the Ruby Track

Published at Jul 13 2018 · 3 comments
Instructions
Test suite
Solution

Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

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: 1.

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

(NXX)-NXX-XXXX

where 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
  • 613-995-0253
  • 1 613 995 0253
  • 613.995.0253

should all produce the output

6139950253

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:

ruby phone_number_test.rb

To include color from the command line:

ruby -r minitest/pride phone_number_test.rb

Source

Event Manager by JumpstartLab http://tutorials.jumpstartlab.com/projects/eventmanager.html

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

phone_number_test.rb

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
class PhoneNumber
  VALID_PHONE_NUMBER = /^([2-9]\d\d){2}\d{4}$/

  def self.clean(number)
    numbers = number.gsub(/\D/, "").sub(/^1/, "")
    numbers[VALID_PHONE_NUMBER]
  end
end

module BookKeeping
  VERSION = 2
end

Community comments

Find this solution interesting? Ask the author a question to learn more.
Avatar of lujanfernaud

Using string[regexp], the matching portion of the string is returned. If there is no match, it returns nil.

https://ruby-doc.org/core-2.4.0/String.html#method-i-5B-5D

Avatar of misterwolf

really good! I have a question: I prefer check the presence of some not-allowed symbols before starting the routines (such as gsub and others) to save time on operations. Do you think it can be negligible?

Avatar of lujanfernaud

@misterwolf commented:

really good! I have a question: I prefer check the presence of some not-allowed symbols before starting the routines (such as gsub and others) to save time on operations. Do you think it can be negligible?

I don't know. It would be interesting to check the benchmarks and see if there's any significant difference.

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