How to quickly zero out an array?

Try Array.Clear():

Sets a range of elements in the Array to zero, to false, or to null (Nothing in Visual Basic), depending on the element type.

• C++: memset(array, 0, array_length_in_bytes);

• C++11: array.fill(0);

• C#: Array.Clear(array, startingIndex, length);

• Java: Arrays.fill(array, value);