String


forEach


const toBin = (inputDecimal) => {
  return Number(inputDecimal).toString(2);
};

var countBits = function (n) {
  let res = toBin(n);
  let count = 0;

  [...res].forEach((t) => {
    console.log(t);
    if (+t === 1) {
      count++;
    }
  });
  return count;
};