function isOdd(n) {
  return n % 2;
}

let numbers = [1, 2, 3, 4, 5];

let odd = [];

for (let i = 0, total = numbers.length; i < total; i = i + 1) {
  let number = numbers[i];
  if (isOdd(number)) {
    odd.push(number);
  }
}