1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.Threading.Tasks; 6  7 using System.Collections; 8  9 namespace day0110 {11     class Class2412     {13         static void Main(string[] args)14         {15             ArrayList list = new ArrayList();16             list.Add(new Student("zhangsan", 23));17             list.Add(new Student("lisi", 24));18             list.Add(new Student("wangwu", 25));19 20             foreach(Student temp in list)21             {22                 Console.WriteLine(temp.ToString());23             }24 25             Console.WriteLine();26             //其实调用的对象是Object类型的 因为重写了Object的ToString()方法 所以调用时有多态的存在27             Console.WriteLine(list[2].ToString());28             //验证了返回的对象类型为Object类型 要调用方法 需要强制类型转换才行29             ((Student)list[2]).GetInfo();30             Console.ReadKey();31         }32     }33     public class Student34     {35         private string name;36         private int age;37         public string Name { get; set; }38         public int Age { get; set; }39         public Student()40         {41 42         }43         public Student(string name,int age)44         {45             Name = name;46             Age = age;47         }48         public override string ToString()49         {50             return "name: " + Name + " age: " + Age;51         }52         public void GetInfo()53         {54             Console.WriteLine("name is {0} age is {1}", Name, Age);55         }56     }57 }