C#合并数组

C#数组合并-简单说
遇到了需要合并数组的问题，看了这篇帖子有点灵感，记录一下。

int[] i = new int[] { 2, 1 };
int[] j = new int[] { 2, 3 };

List<int> r = new List<int>();
r.AddRange(i);
r.AddRange(j);
int[] l = r.ToArray();//List合并数组
Console.WriteLine("List合并");
foreach (var n in l)
{
    Console.WriteLine(n);
}

Console.WriteLine("Union合并");
int[] u = i.Union(j).ToArray(); //剔除重复项 
foreach (var n in u)
{
    Console.WriteLine(n);
}

Console.WriteLine("Concat合并");
int[] c = i.Concat(j).ToArray(); //保留重复项
foreach (var n in c)
{
    Console.WriteLine(n);
}