在列表列表中追加列表

list1 = [1, 2, 3]
list2 = [4, 5, 6]
new_list = list1 + list2
print(new_list)

list1 = [1, 2, 3]
list2 = [4, 5, 6]
list1.extend(list2)
print(list1)

List<Integer> list1 = new ArrayList<>(Arrays.asList(1, 2, 3));
List<Integer> list2 = new ArrayList<>(Arrays.asList(4, 5, 6));
list1.addAll(list2);
System.out.println(list1);

let list1 = [1, 2, 3];
let list2 = [4, 5, 6];
let newList = list1.concat(list2);
console.log(newList);

List<int> list1 = new List<int>() { 1, 2, 3 };
List<int> list2 = new List<int>() { 4, 5, 6 };
List<int> newList = list1.Concat(list2).ToList();
Console.WriteLine(string.Join(", ", newList));

List<int> list1 = new List<int>() { 1, 2, 3 };
List<int> list2 = new List<int>() { 4, 5, 6 };
List<int> newList = list1 + list2;
Console.WriteLine(string.Join(", ", newList));