Nối (Concatenate) hai List trong C#

Dùng AddRange() để nối list2 vào list1 (mutate list1).

var products1 = new List<string> { "Belts", "Tshirt", "Trousers" };
var products2 = new List<string> { "Footwear", "Electronics" };

products1.AddRange(products2);

Ví dụ hoàn chỉnh

using System.Collections.Generic;
using System;

namespace Demo
{
    public static class Program
    {
        public static void Main()
        {
            var products1 = new List<string> { "Belts", "Tshirt", "Trousers" };
            var products2 = new List<string> { "Footwear", "Electronics" };
            
            Console.WriteLine("List1:"); foreach (var p in products1) Console.WriteLine(p);
            Console.WriteLine("List2:"); foreach (var p in products2) Console.WriteLine(p);
            
            products1.AddRange(products2);
            Console.WriteLine("Nối:"); foreach (var p in products1) Console.WriteLine(p);
        }
    }
}

Kết quả

List1: Belts Tshirt Trousers
List2: Footwear Electronics
Nối: Belts Tshirt Trousers Footwear Electronics

So sánh phương pháp nối: