Map方法仅显示列表中的一项

const numbers = [1, 2, 3, 4, 5];
const doubledNumbers = numbers.map(num => num * 2);
console.log(doubledNumbers); // [2, 4, 6, 8, 10]

numbers = [1, 2, 3, 4, 5]
doubled_numbers = list(map(lambda num: num * 2, numbers))
print(doubled_numbers)  # [2, 4, 6, 8, 10]

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
List<Integer> doubledNumbers = numbers.stream()
                                       .map(num -> num * 2)
                                       .collect(Collectors.toList());
System.out.println(doubledNumbers); // [2, 4, 6, 8, 10]