Is Array.Copy() faster than for loop, for 2D arrays?

Question

I recently changed

        this.FieldValues = new object[2, fieldValues.GetUpperBound(1) + 1];
        for (int i = 0; i < FieldCount; i++)            
           


        

Answer 1

In your particular example, there is a factor that might (in theory) indicate the for loop is faster.

Array.Copy is a O(n) operation while your for loop is O(n/2), where n is the total size of you matrix.

Array.Copy needs to loop trough all the elements in your two-dimensional array because:

When copying between multidimensional arrays, the array behaves like a long one-dimensional array, where the rows (or columns) are conceptually laid end to end. For example, if an array has three rows (or columns) with four elements each, copying six elements from the beginning of the array would copy all four elements of the first row (or column) and the first two elements of the second row (or column).