armstrongNumber.js

/*
An Armstrong number is a number that is the sum of its own digits each raised to the power of the number of digits.

For example:

9 is an Armstrong number, because 9 = 9^1 = 9
10 is not an Armstrong number, because 10 != 1^2 + 0^2 = 1
153 is an Armstrong number, because: 153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153
154 is not an Armstrong number, because: 154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190

Write some code to determine whether a number is an Armstrong number.
*/

const isArmstrongNumber = (number) => {
  const allNumbers = String(number).split('');
  let sum = 0;
  for(let i=0; i<allNumbers.length; i++) {
    sum += Number(allNumbers[i])**allNumbers.length;
  }
  return sum === number ? true : false;
};