const findLargestDifference = (array) => {
  // Check if the array is empty or has only one element
  if (array.length < 2) {
    throw new Error('Array must have at least two elements to find a difference.');
  }

  // Initialize variables to store the minimum and maximum values
  let [min, max] = [array[0], array[0]];

  // Iterate through the array to find the minimum and maximum values
  for (const num of array) {
    if (num > max) {
      max = num;
    }
    if (num < min) {
      min = num;
    }
  }

  // Return the difference between the maximum and minimum values
  return max - min;
};

let age = 50;
function printAge() {
  console.log(age);
  let age = 30;
}
printAge();

// Example usage
const numberArray = [10, 8, 6, 3, 9, 12, 3];
const largestDifference = findLargestDifference(numberArray);
console.log(largestDifference); // Output: 9 (12 - 3)