我正在阅读为什么Java中的数组协方差不好(Why are arrays covariant but generics are invariant?)。如果Dog是Animal的子类型,则Dog[]是Animal[]的子类型。这是一个问题,因为可以这样做: Animal[] animals = new Dog[1];
animals[0] = new Cat();
这与正确实施的泛型不同。
类 public class Building
{
public string Name = "Not To Be Seen";
...
}
public class School: Building
{
public int NoOfRooms = 200;
public string Address = "123 Main St.";