title: List<T> using inside a class
body: <p>I found a code sample about using List inside a class.There are codes what i don't understand.Name and Description fields have value inside List defination but Album field have not a value.(</p>
  
  <p><code>new genre { Name = "Rock" , Description = "Rock music", Album?? }</code></p>
  
  <p>).Why?</p>
  
  <pre><code>public class Genre
  {
      public string  Name { get; set; }
      public string  Description { get; set; }
      public List&lt;Album&gt; Albums { get; set; }
  }
  
  public class Album
  {
      public string  Title { get; set; }
      public decimal  Price { get; set; }
      public Genre  Genre { get; set; }
  }
  
  var genre = new List&lt;Genre&gt;
  {
      new genre { Name = "Rock" , Description = "Rock music" },
      new genre { Name = "Classic" , Description = "Middle ages music" }
  };
  
  new List&lt;Album&gt;
  {
      new Album { Title = "Queensrÿche", Price = 8.99M, Genre = genre.Single(g =&gt; g.Name == "Rock") },
      new Album { Title = "Chopin", Price = 8.99M, Genre = genre.Single(g =&gt; g.Name == "Classic") }
  };
  </code></pre>