C#

[StructLayout(LayoutKind.Seqential, CharSet=CharSet.Ansi)]
public struct Transaction {
  [MarshalAs(UnmanagedType.ByValTStr, SizeConst=21)] public string card_number;
  [MarshalAs(UnmanagedType.U4)] public int card_expirymonth;
  [MarshalAs(UnmanagedType.U4)] public int card_expiryyear;
}

public Database() {
  LoadStaff();
}

public Database() {
  StaffNames = new string[0]
}

public class MyClass {
  public int data;
  
  public MyClass() { }
}

public void Tests() {
  MyClass foo = new MyClass();
  foo.data = 1;

  System.Console.WriteLine("foo = {0}", foo.data);

  MyClass bar = new MyClass();
  bar.data = 2;

  System.Console.WriteLine("foo = {0}", foo.data);
  System.Console.WriteLine("bar = {0}", bar.data);
}

C:\Documents and Settings\gavin\My Documents\Visual Studio Projects\LTBRMaintenance\EditUser.cs(202): Static member 
'LTBRMaintenance.Database.StaffNames' cannot be accessed with an instance reference; qualify it with a type name instead

//Database.cs
public class Database
{
public static string[] StaffNames;

//EditUser.cs
Database sn = new Database();
int uBound = sn.StaffNames.GetUpperBound(0);