Extremely fast way to clone the values of a jagged array into a second array?

Question

I am currently working on an application that is responsible for calculating random permutations of a jagged array.

Currently the bulk of the time in the applicati

Answer 1

You can use Array.Clone for the inner loop:

public static int[][] CopyArray(this int[][] source)
{
    int[][] destination = new int[source.Length][];
    // For each Row
    for(int y = 0;y < source.Length;y++)
    {
        destination[y] = (int[])source[y].Clone();
    }
    return destination;
}

Another alternative for the inner loop is Buffer.BlockCopy, but I haven't measured it's performance against Array.Clone - maybe it's faster:

destination[y] = new int[source[y].Length];
Buffer.BlockCopy(source[y], 0, destination[y], 0, source[y].Length * 4);

Edit: Buffer.BlockCopy takes the number for bytes to copy for the count parameter, not the number of array elements.