switch (expression)
{
  case value1:
    statement 1;
    break;
  case value2:
    statement 2;
    statement 3;
    break;
  default:
    statement 4;
    break;
}

try
            {
                Console.WriteLine("nice started");
                int l = 12;
                throw new Exception("there are problem");
            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally // called at the end and don't care if is their exception or not
            {
                Console.WriteLine("nice finished");
            }

string[] languages = { "Java", "C#", "Python", "C++", "JavaScript" };
foreach (string lang in languages)
{
    Console.WriteLine(lang);
}

Span<int> arr = stackalloc int[]{ 1, 1, 2, 3, 5, 8 };
foreach(ref int n in arr)
{
    n *= 2;
}
foreach(ref readonly var n in arr)
{
    Console.WriteLine(n);
}

for (int i = 0; i <= 10; i++)
{
    Console.WriteLine(i);
    if (i == 5)
    {
        goto printmessage;
    }
}
printmessage:
    Console.WriteLine("The goto statement is executed");

IEnumerable<int> GetNumbers()
{
    for (int i = 1; i <= 100; ++i)
    {
        Thread.Sleep(1000);
        Console.WriteLine($"Produced: {i}");
        yield return i;
    }
}
foreach(var i in GetNumbers().Take(5))
{
    Console.WriteLine($"Consumed: {i}");
}

using System;

class DisposableDemoClass : IDisposable
{
	public void Dispose()
	{
		Console.WriteLine("Dispose called!");
	}
}

class Hello 
{
    static void Main() 
    {
		using(var disp = new DisposableDemoClass())
		{
		}
    }
}