day_12.js

// // Given a number from 0 to 999,999,999,999, spell out that number in English.

// Given a number from 0 to 999,999,999,999, spell out that number in English.
// Instructions
// Given a number from 0 to 999,999,999,999, spell out that number in English.

// Step 1
// Handle the basic case of 0 through 99.

// If the input to the program is 22, then the output should be 'twenty-two'.

// Your program should complain loudly if given a number outside the blessed range.

// Some good test cases for this program are:

// 0
// 14
// 50
// 98
// -1
// 100
// Step 2
// Implement breaking a number up into chunks of thousands.

// So 1234567890 should yield a list like 1, 234, 567, and 890, while the far simpler 1000 should yield just 1 and 0.

// The program must also report any values that are out of range.

// Step 3
// Now handle inserting the appropriate scale word between those chunks.

// So 1234567890 should yield '1 billion 234 million 567 thousand 890'

// The program must also report any values that are out of range. It's fine to stop at "trillion".

// Step 4
// Put it all together to get nothing but plain English.

// 12345 should give twelve thousand three hundred forty-five.

// The program must also report any values that are out of range.


const ones = [
    "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
    "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen",
    "seventeen", "eighteen", "nineteen",
  ];
  const tens = [
    "", "", "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety",
  ];
  const sep = [
    "", " thousand ", " million ", " billion ", " trillion ", " quadrillion ", " quintillion ", " sextillion ",
  ];
  
  const sayNumberInEnglish = (number) => {
      let arr = [], str = "", i = 0;
      if (number.length === 0) {
        return;
      }
  
      number = parseInt(number, 10);
      if (isNaN(number)) {
        return;
      }
  
      while(number){
        arr.push(number%1000)
        number = parseInt(number/1000,10)
      }
  
      while(arr.length){
        str = calc(arr.shift()) + sep[i++] + str;
      }
  
      return str;
    };
  
    function calc (num) {
      let x = Math.floor(num/100);
      let y = Math.floor(num/10)%10
      let z = (num%10)
      let word = (x > 0 ? ones[x] + ' hundred ' : "") + (y >= 2 ? tens[y] + '-' + ones[z] : ones[10*y+z])
      return word;
    }
  
    console.log(`5635 in english is: ${sayNumberInEnglish(5635)}`);