9.Numbers as Words

let input = [
  '290',
];

let p = console.log;
let gets = this.gets || ((arr, index) => () => arr[index++])(input, 0);

let numberStr = gets();
let len = numberStr.length;

let unitsObj = {
  '0': 'zero',
  '1': 'one',
  '2': 'two',
  '3': 'three',
  '4': 'four',
  '5': 'five',
  '6': 'six',
  '7': 'seven',
  '8': 'eight',
  '9': 'nine',
};

let dozensObj = {
  '10': 'ten',
  '20': 'twenty',
  '30': 'thirty',
  '40': 'forty',
  '50': 'fifty',
  '60': 'sixty',
  '70': 'seventy',
  '80': 'eighty',
  '90': 'ninety',
};

let numbers10to19 = {
  '10': 'ten',
  '11': 'eleven',
  '12': 'twelve',
  '13': 'thirteen',
  '14': 'fourteen',
  '15': 'fifteen',
  '16': 'sixteen',
  '17': 'seventeen',
  '18': 'eighteen',
  '19': 'nineteen',
};

if (len == 3) {
  if (numberStr[2] === '0' && numberStr[1] === '0') {
    p(`${unitsObj[numberStr[0]]} hundred`);
  } else if (numberStr[1] === '0') {
    p(`${unitsObj[numberStr[0]]} hundred and ${unitsObj[numberStr[2]]}`);
  } else if (numberStr[2] === '0') {
    if (numberStr[1] === '1') {
      p(`${unitsObj[numberStr[0]]} hundred and ten`);
    } else {
      p(`${unitsObj[numberStr[0]]} hundred and ${dozensObj[numberStr[1] + '0']}`);
    }
  } else {
    if (numberStr[1] === '1') {
      p(`${unitsObj[numberStr[0]]} hundred and ${numbers10to19['1' + numberStr[2].toString()]}`);
    } else {
      p(`${unitsObj[numberStr[0]]} hundred and ${dozensObj[numberStr[1] +
        '0']} ${unitsObj[numberStr[2]]}`);
    }
  }
} else if (len === 2) {
  if (numberStr[1] === '0') {
    p(`${dozensObj[numberStr[0] + '0']}`);
  } else if (numberStr[0] === '1') {
    p(`${numbers10to19['1' + numberStr[1].toString()]}`);
  } else {
    p(`${dozensObj[numberStr[0] + '0']} ${unitsObj[numberStr[1]]}`);
  }
} else {
  p(`${unitsObj[numberStr[0]]}`);
}