public class Student  {    public Student(){}    public Student(String name,int age,String hobby)  {     this.Name = name;     this.Age = age;     this.Hobby = hobby;    }    private String name;    public String Name    {     get{return name;}     set{name = value;}    }    private int age;    public int Age    {     get{return age;}     set{age = value;}    }    private String hobby;    public String Hobby    {     get{return hobby;}   set{hobby = value;}  }  public void say()  {   Console.WriteLine("大家好，我是'{0}'，今年{1}歲，我喜歡'{2}'",   this.Name,this.Age,this.Hobby);  }}

using System.Collections;public class TestStudent{    public static void main(String args [])   {    //建立ArrayList對象    ArrayList students = new ArrayList();    //實例化幾個Student類對象    Student rose = new Student("rose",25,"reading");   Student jack = new Student("jack",28,"singing");   Student mimi = new Student("mimi",26,"dancing");   //利用ArrayList類的add()方法添加元素    students.add(rose);    students.add(jack);    students.add(mimi);    //利用ArrayList的Count屬性查看該集合中的元素數量   int number = students.Count;     Console.WriteLine("共有元素" + number + "個");    //讀取單個元素,因為存入ArrayList中的元素會變為Object類型,   //所以，在讀取時間，    Student stu = students[0] as Student;    stu.say();    //遍歷元素 -- 通過索引    for(int i = 0;i < students.Count;i ++)    {     Student a = students[i] as Student;     a.say();    }    //利用foreach循環    foreach(Object o in students)    {      Student b = o as Student;      b.say();    }    //刪除元素 通過索引刪除    students.removeAt(0);    //刪除元素,  通過對象名    students.remove(jack);    //清空元素    students.Clear();    //我們知道，ArrayList的容量會隨著我們的需要自動按照一定規律   //進行填充,當我們確定不再添加元素時，我們要釋放多余的空間   //這就用到了Capacity屬性和TrimtoSize()方法    //利用Capacity屬性可以查看當前集合的容量      //利用TrimtoSize()方法可以釋放多余的空間    //查看當前容量    int number = students.Capacity;   //去除多余的容量   students.TrimtoSize();   } }