let numbers = [1, 4, 9, 16];
      let myNumber = 3;
      let closest = numbers[0];
      let closestDiff = Math.abs(closest - myNumber);
      for (let i = 0; i < numbers.length; i++) {
         let diff = Math.abs(numbers[i] - myNumber);
         if (diff < closestDiff) {
            closestDiff = diff;
            closest = numbers[i];
         }
      }