初始化c#数组为其索引值，而无需循环或递归? [英] Initialize c# array to its index value without loops or recursions?

问题描述

嘿，我知道C#首次初始化时会将数组初始化为default(T).
(int [] ar = new int [n]);

有什么方法可以初始化数组:
a [0] = 0
a [1] = 1
...
a [n] = n

没有任何循环或递归?

谢谢

顺便说一句，我的解决方案与此类似:

hey, i know that C# inits the array to the default(T) when is first initialized.
(int[] ar = new int[n]);

is there any way to initialize the array:
a[0] = 0
a[1] = 1
...
a[n] = n

without any loops or recursion?

thanks

by the way, my solution was similar to this:

public class intArray
{
  int[] arr;
  bool[] gotArray;

  public intArray(int size)
  {
    arr = new int[size];
    gotArray = new bool[size];
  }

  // dont remember exactly the [] syntax but:
  public int operator [](int index)
  {
     get
     {
        if (!gotArray[index])
           return index;
        else
           return arr[index];
     }
     set
     {
        arr[index] = value;
        gotArray[index] = true;
     }
     
  }

}

但似乎有更好的解决方法

but it seems that there''s a better solution

推荐答案

您可以使用可为空的int
来剪切原始数组中的bool数组.

You could cut out the bool array in your original by using a nullable int

public class intArray
    {
          int?[] arr;
           
          public intArray(int size)
          {
                arr = new int?[size];
          }

          public int this[int index]
          {
                get
                {
                    if (arr[index] == null)
                        arr[index] = index;
                    
                    return (int)arr[index];
                }
                set
                {
                    arr[index] = value;
                }
          }
    }


    class Program
    {
        static void Main(string[] arguments)
        {
            intArray iarr = new intArray(10);

            for (int i = 0; i < 10; ++i)
                Console.Out.WriteLine(iarr[i]);

            Console.ReadKey();
        }
    }

您的意思是:

You mean something like:

int[] ar = new int[3] { 0, 1, 2 };

int[] ar = new int[3];
ar.Initialize();

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