C# - C Sharp: Mảng răng cưa

using System;

namespace ConsoleApp2
{
  class Program {
    static void Main(string[] args) {
      //Mảng răng cưa (Jagged):
      string[][] str = new string[2][];
      str[0] = new string[]{"AB", "CD", "EF"};
      str[1] = new string[]{"12", "34"};
      for (int i = 0; i < str.GetLength(0); i++) {
        foreach(string s in str[i])
        {
          Console.Write(s + "  ");
        }
        Console.WriteLine();
      }
      Console.WriteLine("===========");
      foreach(string s in str[0])
      {
        Console.WriteLine(s);
      }
    }
  }
}