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to Phone Number in the JavaScript Track

Published at Jul 13 2018 · 0 comments
Test suite


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


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


Note: As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.


Go through the setup instructions for JavaScript to install the necessary dependencies:


Running the test suite

The provided test suite uses Jasmine. You can install it by opening a terminal window and running the following command:

npm install -g jasmine

Run the test suite from the exercise directory with:

jasmine phone-number.spec.js

In many test suites all but the first test have been marked "pending". Once you get a test passing, activate the next one by changing xit to it.


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.


var PhoneNumber = require('./phone-number');

describe('PhoneNumber()', function () {
  it('cleans the number', function () {
    var phone = new PhoneNumber('(223) 456-7890');

  xit('cleans numbers with dots', function () {
    var phone = new PhoneNumber('223.456.7890');

  xit('cleans numbers with multiple spaces', function () {
    var phone = new PhoneNumber('223 456   7890   ');

  xit('invalid when 9 digits', function () {
    var phone = new PhoneNumber('123456789');

  xit('invalid when 11 digits does not start with a 1', function () {
    var phone = new PhoneNumber('22234567890');

  xit('valid when 11 digits and starting with 1', function () {
    var phone = new PhoneNumber('12234567890');

  xit('valid when 11 digits and starting with 1 even with punctuation', function () {
    var phone = new PhoneNumber('+1 (223) 456-7890');

  xit('invalid when more than 11 digits', function () {
    var phone = new PhoneNumber('321234567890');

  xit('invalid with letters', function () {
    var phone = new PhoneNumber('123-abc-7890');

  xit('invalid with punctuations', function () {
    var phone = new PhoneNumber('123-@:!-7890');

  xit('invalid if area code does not start with 2-9', function () {
    var phone = new PhoneNumber('(123) 456-7890');

  xit('invalid if exchange code does not start with 2-9', function () {
    var phone = new PhoneNumber('(223) 056-7890');
function PhoneNumber(raw_input) {
  'use strict';

  var invalid = '0000000000';

  function number() {
    number = strip_punctuation();

    if (number.length == 10) {
      return number;
    } else if (number.length == 11 && number[0] === '1') {
      return number.slice(1);
    } else {
      return invalid;

  function toString() {
    var areaCode = this.areaCode();
    var partOne = this.number().substr(3, 3);
    var partTwo = this.number().substr(6);
    return "(" + areaCode + ") " + partOne + "-" + partTwo;

  function areaCode() {
    return number().substring(0, 3);

  function strip_punctuation() {
    var re = /[\.\-\(\)\s]/g
    return raw_input.replace(re, '')

  return {
    number: number,
    areaCode: areaCode,
    toString: toString

module.exports = PhoneNumber

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