New in .NET 7 [7]: Auto-Default Structs in C# 11.0

Prior to C# 11.0, a parameterless constructor in a structure had to explicitly assign a value to all fields and properties not initialized in the declaration, such as ID and Name in the following example:

struct Experte
 {
  public int ID;
  public string Name { get; set; }
  public List Themen { get; set; } = new List(); 
 
  public List MitarbeiterTeam { get; set; } = 
    new List();

  struct Adresse
  {
   public string Strasse { get; set; }
   public string PLZ { get; set; }
   public string Ort { get; set; }
  }

  public Experte()
  {
   ID = 0;
   Name = "unbekannt";
  }

  public Experte(int id, string name)
  {
   ID = id;
   Name = name;
  }

  public int ThemenAnzahl { get { return this.Themen.Count; } }
  public string GetThemenString()
  {
   return String.Join(", ", this.Themen);
  }
 }

This has changed with C# 11.0: The data members (fields and properties) of structures no longer have to be explicitly initialized in their own constructors if they do not have initialization values ​​when they are declared.

Since C# 11.0, all fields and properties that are not explicitly initialized are initialized with their default values. Microsoft calls the feature Auto-Default Structs.

(rme)