Convert 2 dimensional array

Question

What is selectMany.ToArray() method? Is it a built in method in C#?

I need to convert two dimensional array to one dimensional array.

Answer 1

If you mean a jagged array (T[][]), SelectMany is your friend. If, however, you mean a rectangular array (T[,]), then you can just enumerate the date data via foreach - or:

int[,] from = new int[,] {{1,2},{3,4},{5,6}}; int[] to = from.Cast<int>().ToArray(); 

Answer 2

SelectMany is a projection operator, an extension method provided by the namespace System.Linq.

It performs a one to many element projection over a sequence, allowing you to "flatten" the resulting sequences into one.

You can use it in this way:

int[][] twoDimensional = new int[][] {                                        new int[] {1, 2},                                       new int[] {3, 4},                                       new int[] {5, 6}                                      };  int [] flattened = twoDimensional.SelectMany(x=>x).ToArray();