New in .NET 9.0 (9): Inchialization with arrays with index operators in C# 13.0

By now, a initialization of volumes such as arrays with index × = y Take place. C# 13.0 also has an array Arbhikaran with an index from the end. (^x) = y Possible with index operator ^This has been since C# 8.0.

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However, the new syntax is possible only with the start of the object, not with other allocation.

The following code example shows the object volume with the exposure from the front from the front × And from the end (^x),

namespace NET9_Console.CS13;
 
internal class CS13_Indexer
{
 
 class ZahlenGenerator
 {
  public string() Ziffern = new string(10);
 }
 
 /// 

 /// C# 13.0: Objekt-Initialisierung mit Index vom Ende (^x) ("Implicit Indexer Access in Object Initializers")
 /// 
 public void Run()
 {
  CUI.Demo(nameof(CS13_Indexer));
 
  CUI.H2("Array-Initialisierung mit Indexer von vorne nach hinten");
  var dAlt = new ZahlenGenerator()
  {
   Ziffern = {
        (0) = "null",
        (1) = "eins",
        (2) = "zwei",
        (3) = "drei",
        (4) = "vier",
        (5) = "fünf",
        (6) = "sechs",
        (7) = "sieben",
        (8) = "acht",
        (9) = "neun",
    }
  };
 
  foreach (var z in dAlt.Ziffern)
  {
   Console.WriteLine(z);
  }
 
  CUI.H2("NEU: Array-Initialisierung mit Indexer von hinten nach vorne");
  var dNeu = new ZahlenGenerator()
  {
   Ziffern = {
         (^1) = "neun",
         (^2) = "acht",
         (^3) = "sieben",
         (^4) = "sechs",
         (^5) = "fünf",
         (^6) = "vier",
         (^7) = "drei",
         (^8) = "zwei",
         (^9) = "eins",
         (^10) = "null"
   }
  };
  foreach (var z in dNeu.Ziffern)
  {
   Console.WriteLine(z);
  }
 
  CUI.H2("NEU: Array-Initialisierung mit Indexer in beide Richtungen");
  var dNeu2 = new ZahlenGenerator()
  {
   Ziffern = {
         (^1) = "neun",
         (^2) = "acht",
         (^3) = "sieben",
         (^4) = "sechs",
         (^5) = "fünf",
         (4) = "vier",
         (3) = "drei",
         (2) = "zwei",
         (1) = "eins",
         (0) = "null"
   }
  };
 
  foreach (var z in dNeu2.Ziffern)
  {
   Console.WriteLine(z);
  }
 
  CUI.H2("NEU: Array-Befüllung zu einem späteren Zeitpunkt");
 
  // erstelle ein Array von int mit 10 Elementen
  int() array1 = new int(10) { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
  // das geht nicht, Syntax nur bei Objektinitialisierung im Rahmen der Instanziierung erlaubt
  //array1 = {
  //       (^1) = 9,
  //       (^2) = 8,
  //       (^3) = 7,
  //       (^4) = 6,
  //       (^5) = 5,
  //       (0) = 0,
  //       (1) = 1,
  //       (2) = 2,
  //       (3) = 3,
  //       (4) = 4
  // }
 
  // hier geht nur das:
  array1(^1) = 9;
  array1(^2) = 8;
  array1(^3) = 7;
  array1(^4) = 6;
  array1(^5) = 5;
  array1(0) = 0;
  array1(1) = 1;
  array1(2) = 2;
  array1(3) = 3;
  array1(4) = 4;
 
  foreach (var item in array1)
  {
   CUI.LI(item);
  }
 }
}

(RME)