30秒学会 C# 片段 – Initialize2DArray

Initializes a 2D array of the given width, height and value.

Use Enumerable.Repeat() to repeat value width times, convert to an array and repeat height times using the same method.
Use IEnumerable.Select() and IEnumerable.First() to convert the jagged array to a 2D array.

代码实现

using System.Linq;

public static partial class _30s 
{
  public static T[,] Initialize2DArray<T>(int width, int height, T value) 
  {
    return new [] { new T [height, width] }
      .Select(_ => new { x = _, y = Enumerable.Repeat(
          Enumerable.Repeat(value, width).ToArray(), height
        )
        .ToArray()
        .Select((a, ia) => a.Select((b, ib) => _[ia, ib] = b).Count()).Count() }
      )
      .Select(_ => _.x)
      .First();
  }
}

使用样例

_30s.Initialize2DArray(2, 3, 5); // { {5, 5}, {5, 5}, {5, 5} }