--- id: 5900f37d1000cf542c50fe90 title: 'Problem 17: Number letter counts' challengeType: 5 forumTopicId: 301804 dashedName: problem-17-number-letter-counts --- # --description-- If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total. If all the numbers from 1 to given `limit` inclusive were written out in words, how many letters would be used? **Note:** Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage. # --hints-- `numberLetterCounts(5)` should return a number. ```js assert(typeof numberLetterCounts(5) === 'number'); ``` `numberLetterCounts(5)` should return 19. ```js assert.strictEqual(numberLetterCounts(5), 19); ``` `numberLetterCounts(150)` should return 1903. ```js assert.strictEqual(numberLetterCounts(150), 1903); ``` `numberLetterCounts(1000)` should return 21124. ```js assert.strictEqual(numberLetterCounts(1000), 21124); ``` # --seed-- ## --seed-contents-- ```js function numberLetterCounts(limit) { return true; } numberLetterCounts(5); ``` # --solutions-- ```js function numberLetterCounts(limit) { const dictionary = { 0: '', 1: 'one', 2: 'two', 3: 'three', 4: 'four', 5: 'five', 6: 'six', 7: 'seven', 8: 'eight', 9: 'nine', 10: 'ten', 11: 'eleven', 12: 'twelve', 13: 'thirteen', 14: 'fourteen', 15: 'fifteen', 16: 'sixteen', 17: 'seventeen', 18: 'eighteen', 19: 'nineteen', 20: 'twenty', 30: 'thirty', 40: 'forty', 50: 'fifty', 60: 'sixty', 70: 'seventy', 80: 'eighty', 90: 'ninety', 1000: 'onethousand' }; let numString = ''; function convertToString(num) { // check dictionary for number if (dictionary[num]) { return dictionary[num]; } else { const hundreds = Math.floor(num / 100); const tens = Math.floor((num / 10) % 10) * 10; const remainder = num % 10; let tempStr = ''; if (hundreds === 0) { tempStr += dictionary[tens] + dictionary[remainder]; } else { tempStr += dictionary[hundreds] + 'hundred'; if (tens !== 0 || remainder !== 0) { tempStr += 'and'; } if (tens < 20) { const lessThanTwenty = tens + remainder; tempStr += dictionary[lessThanTwenty]; } else { tempStr += dictionary[tens] + dictionary[remainder]; } } return tempStr; } } for (let i = 1; i <= limit; i++) { numString += convertToString(i); } return numString.length; } ```