During a code challenge I was tasked creating a function (details after) and tried to do it recursively, I had to change gears but to prove to myself that I could do it, here it is. ~Challenge: "Write a function numericReduction(number) that takes a number and adds the digits together until only 1 digit remains and return the number of itteratio…

numericReductionRecursive.js

function numericReduction(num, count=1) {
	if(isNaN(num)) throw new Error('num must be a valid integer')
  
	var new_num = (num+'').split('').reduce((total, value)=>total+=parseInt(value),0)
  
  if (new_num >= 10) {
  	return numericReduction(new_num, count + 1)
  } else {
    return count;
  }
}

numericReduction(99) // 99 → 18 → 9 : returns 2
numericReduction(101) // 101 → 2 : returns 1
numericReduction(199) // 199 → 19 → 10 → 1 : returns 3