function money(s, n) {
  n = n || 0;
  n = n >= 0 && n <= 5 ? n : 2;
  s = parseFloat((s + '').replace(/[^\d\.-]/g, '')).toFixed(n) + '';
  s = s.split('.');
  let l = s[0].split('').reverse(),
    r = s[1] || '',
    t = '';
  for (let i = 0; i < l.length; i++) {
    t += l[i] + ((i + 1) % 3 == 0 && (i + 1) != l.length ? ',' : '');
  }
  return t.split('').reverse().join('') + (r ? ('.' + r) : r);
}

module.exports = money;