Fastest way in c# to clear portions of an array or move portions around

Question

what is the fastest way in c# to manipulate array of short ints? I miss things like memset or mempcy and memmove.

I need to clear (set to 0) portions of an array and move portions around (like shifting values to different indices)

To be more precise: I have a huge array that I have to modify. Sometime I have to clear portions of that array, setting them to 0. Other times I have to shift data around inside the same array. I therefore need to operate on the same Array already allocated

Answer 1

An array in c# will already be allocated with the default value of the type, so memset to 0 is usually irrelevant. You will never get a " dirty " array on construction.

For copy operations, you can use Array.Copy for typed copying or Buffer.Blockcopy for raw byte copying.

Both of these support copying from/to the same array, you just have to be careful not to provide overlapping idices.

Edit:

For clearing out data you can use Array.Clear

Answer 2

For clearing a part of an array you can just use a method like:

public static void Clear(short[] arr, int start, int len) {
  int end = start + len;
  for (int i = start; i < end; i++) arr[i] = 0;
}

For copying, you can use Array.Copy or Buffer.BlockCopy methods. They also handle copying within the same array, even if the source and destination areas overlap.