subtractProductAndSum.js

/** 
 * Problem: 1281. Subtract the Product and Sum of Digits of an Integer
 * Given an integer number n, return the difference between the product of its digits and the sum of its digits.

Example 1:

Input: n = 234
Output: 15 
Explanation: 
Product of digits = 2 * 3 * 4 = 24 
Sum of digits = 2 + 3 + 4 = 9 
Result = 24 - 9 = 15

*/

/**
 * @param {number} n
 * @return {number}
 */
var subtractProductAndSum = function (n) {
  const arr = findDigits(n);
  console.log("arr: ", arr);
  const prod = arr.reduce((acc, num) => acc * num);
  const sum = arr.reduce((acc, num) => acc + num);

  return prod - sum;
};

function findDigits(number) {
  let arr = [];
  while (number > 0) {
    let digit = number % 10;
    number = Math.floor(number / 10);
    arr.push(digit);
  }
  return arr.reverse();
}

console.log(subtractProductAndSum(643));