如何创建一个将每个数字重复两次的数组？

function doubleNumbers(numbers) {
  var result = [];
  for (var i = 0; i < numbers.length; i++) {
    result.push(numbers[i]);
    result.push(numbers[i]);
  }
  return result;
}

var numbers = [1, 2, 3, 4, 5];
var doubledNumbers = doubleNumbers(numbers);
console.log(doubledNumbers); // 输出 [1, 1, 2, 2, 3, 3, 4, 4, 5, 5]