C#数组、集合

数组是一种可以存放同一类型数据集合的数据结构，属于引用类型。

初始化：

          声明一个大小为5的Int型的集合

          int [] numbers=new int[5];

 

 int [] numbers =new int[5]{1,2,3,4,5}；

或者

 int [] numbers ={1,2,3,4,5}

 

 访问：

     使用整形参数的索引器访问数组中的每一个元素（索引值从0开始）

       int [] numbers ={1,2,3,4,5}

      Console.WriteLine(numbers[0]);    //1

      Console.WriteLine(numbers[4]);    //5

泛型 集合 

list<T>

使用时根据实际分配内存

class Program
    {
        static void Main(string[] args)
        {
            Student student1 = new Student(1001, "李1");
            Student student2 = new Student(1002, "李2");
            Student student3 = new Student(1003, "李3");
            Student student4 = new Student(1004, "李4");

            List<Student> stuList = new List<Student>();

            //集合初始化器
            //List<Student> stuList1 = new List<Student>() { student1, student2, student3, student4 };
            stuList.Add(student1);
            stuList.Add(student2);
            stuList.Add(student3);
            stuList.Add(student4);
            stuList.Add(new Student() { StudentName = "李四", StudentId = 1006 });
           
            
            
            //错误的类型
            //stuList.Add(new Teacher() { teacherId = 1005, teacherName = "" });
            Console.WriteLine("元素总数：{0}",stuList.Count);
            stuList.RemoveAt(0);
            stuList.Insert(0, new Student(1005, "张三"));
            foreach (Student item in stuList)
            {
                Console.WriteLine(item.StudentName+"\t"+item.StudentId);
            }
            Console.ReadLine();

        }
    }
    class Student
    {
        public Student()
        { }
        public Student(int stuId,string stuName)
        {
            StudentId = stuId;
            StudentName = stuName;
        }
        public int StudentId { get; set; }
        public string StudentName  { get; set; }
        public int Age { get; set; }
    }
    class Teacher
    {
        public int teacherId { get; set; }
        public string teacherName { get; set; }
    }

Dictionary<K,V>  键值对

   //创建Dictionary集合
            Dictionary<string, Student> stus = new Dictionary<string, Student>();
            stus.Add("李1", student1);
            stus.Add("李2", student2);
            stus.Add("李3", student3);
            stus.Add("李4", student4);
            Console.WriteLine(stus["李3"].StudentName+ "\t\t" +stus["李2"].StudentId);
            Console.WriteLine("************************************");
            foreach (string key in stus.Keys)
            {
                Console.WriteLine(key);
            }
            Console.WriteLine("************************************");
            foreach (Student value in stus.Values)
            {
                Console.WriteLine(value.StudentName+"\t"+value.StudentId);
            }
            Console.ReadLine();

集合的排序

list.sort();

比较器

Class: IComparer<T>