Javascript sum numbers in an array by two digit sequence each

Question

I'm stuck with this exercise, at the end I tell you what is my output but before the description of the exercise, thanks in advance!

DESCRIPTION:

It receives an array with numbers and letters and returns it with its numbers beautified. Letters remain unchanged Beautify process is to reduce a number into a single digit number by adding all its digits together:

123 = 6 because 1+2+3 = 6
9 = 9
9956 = 2 because 9+9+5+6 = 29 -> 2+9 = 11 -> 1+1 = 2
793 = 1 because 7+9+3 = 19 -> 1+9 = 10 -> 1+0 = 1
Example: beautifyNumbers([23,59, 4,'A','b']) returns [5, 5, 4, 'A', 'b']

my CODE:

function beautifyNumbers(array) {

  var newArray = [];
  array.forEach(function(element) {
    // Checks if character is a letter and not a number
    if (typeof element == "number") {
      var sNumber = element.toString();

      for (var i = 0, len = sNumber.length; i < len; i += 1) {
        newArray.push(+sNumber.charAt(i));
        // The "+" sign converts a String variable to a Number, if possible: +'21.2' equals Number(21.2).
        // If the conversion fails, it return NaN.
        // El método charAt() de String devuelve el carácter especificado de una cadena:
        // var name="Brave new world"; name.charAt(0) => 'B'
      }
      console.log(newArray);;
    } else {
      // pushes numbers to the array without making
      // any change to them
      newArray.push(element);
    }
  });
  // returns the array
  return newArray;


}

beautifyNumbers([23, 59, 4, 'A', 'b'])

An the output I receive is => [2, 3, 5, 9, 4, "A", "b"]

Is this the "previous" step before doing the sum or am I doing something wrong?

Answer 1

Hi you can try like this as mentioned by me in comments.

function beautifyNumbers(array) {
  var newArray = [];
  array.forEach(function(element) {
    // Checks if character is a letter and not a number
    if (typeof element == "number") {
      if(element %9 == 0 && element != 0)
        newArray.push(9);
      else 
        newArray.push(element%9);
    } else {
      newArray.push(element);
    }
  });
  return newArray;
}
console.log(beautifyNumbers([1231, 0, 18, 27, 12354, 59, 4, 'A', 'b']))

Edit: Thanks @georg for suggestion.