c sharp official documentation code example

Example 1: c# ?

/*
	A nullable value type T? represents all values of its underlying
    value type T and an additional null value. For example, you can 
    assign any of the following three values to a bool? variable: 
    true, false, or null.
*/

double? pi = 3.14;
char? letter = 'a';

int m2 = 10;
int? m = m2;

bool? flag = null;

Example 2: c#

/* A C# (C-sharp ex.) */ 
using System;
	namespace helloWorld
    {
      class Program
      {
        static void Main()
        {
          Console.WriteLine("What's your age?")
           string age = Console.ReadLine()
            Console.WriteLine($"You are {age} years old!")
        }
      }
    }