Car [] cars ={new AudiA4("AudiA4\t",500,4,0),new PickUpSnow6("PickUpSnow6",450,4,2),new SongHuaRiver("SongHuaRiver",400,0,4)};
Car类型啊,用户自己定义的类。不过成员是Car的子类,多态性,便于使用
大神类型,小白看不懂。