ArrayList list = new ArrayList();//(1)
ArrayList<Student> list = new ArrayList<Student>();//(2)
泛型好处:(1)运行时错误变成编译时错误
(2)list.get(i)时,不用强制转型了,像这样: (Student)list.get(i)
ArrayList list = new ArrayList();//(1)
ArrayList<Student> list = new ArrayList<Student>();//(2)
泛型好处:(1)运行时错误变成编译时错误
(2)list.get(i)时,不用强制转型了,像这样: (Student)list.get(i)