c# 操作符原理及概念

 

1操作符概览

2操作符的本质

操作符的本质是函数（即算法）的简记法

static void Main(string[] args)
        {
            Person people1 = new Person();
            Person people2 = new Person();
            people1.Name = "王小丫";
            people2.Name = "陈雪梅";
            List nation = Person.GetMarry(people1, people2);
            foreach (var p in nation)
            {
                Console.WriteLine(p.Name);
            }
        }
        class Person
        {
            public string Name;
            public static List GetMarry ( Person p1 , Person p2 )
                {
            List people = new List();
                people.Add(p1);
                people.Add(p2);
                for (int i = 0; i < 11; i++)
                {
                    Person chid = new Person();
                    chid.Name = p1.Name + "&" + p2.Name + "&"+i;
                    people.Add(chid);
                }
                return people;
            }
        }

static void Main(string[] args)
        {
            Person people1 = new Person();
            Person people2 = new Person();
            people1.Name = "王小丫";
            people2.Name = "陈雪梅";
            List nation = people1+people2;
            foreach (var p in nation)
            {
                Console.WriteLine(p.Name);
            }
        }
        class Person
        {
            public string Name;
            public static List operator+ ( Person p1 , Person p2 )
                {
            List people = new List();
                people.Add(p1);
                people.Add(p2);
                for (int i = 0; i < 11; i++)
                {
                    Person chid = new Person();
                    chid.Name = p1.Name + "&" + p2.Name + "&"+i;
                    people.Add(chid);
                }
                return people;
            }
        }

操作符不能脱离与它关联的数据类型（操作符与固定数据类型的一套基本算法的简记法）

static void Main(string[] args)
        {
            int x = 5;
            int y = 4;
            int z = x / y;
            Console.WriteLine(z);//输出1
            double a = 5;
            double b = 4;
            double c = a / b;
            Console.WriteLine(c);//输出1.25
        }

 

3操作符的优先级

带有赋值功能运算符 右向左 

x+=y+=z

x+=y

+不带赋值功能运算符  左向右 

x=x+y+z

4统计操作符的运算顺序

5各类操作符的示例

.点 成员访问操作符

1外层空间名称的子集空间名称

访问名称空间的类型  访问类型的静态成员  访问对象的成员

 System.IO.File.Create("D:\\helo.txt");
            //System外层空间名称//IO子集空间 //File名称空间的类型//Create访问类型的静态成员//Create访问对象的成员

f(x) 方法调用操作符 方法函数（参数）

 static void Main(string[] args)
        {
            Person c = new Person();
            double x=    c.Add(3.0,5.0);
            Console.WriteLine(x);
            //委托
            Action myaction = new Action(c.PrintHellod);
            myaction();

        }
        class Person
        {
            public double Add(double a, double b)
            {
                return a + b;
            }
            public void PrintHellod()
            {
                Console.WriteLine("Hello");
            }
        }

o[x]元素访问操作符

static void Main(string[] args)
        {
            //访问数组
            int[] myintArray = new int[10];
            int[] myintArray1 = new int[] { 1, 2, 3, 4, 5 };
            Console.WriteLine(myintArray1[0]);
            //访问字典
            Dictionary perdic = new Dictionary();
            for (int i = 1; i <= 100; i++)
            {
                Person per = new Person();
                per.Name = "s_" + i.ToString();
                per.Scone = 100 + i;
                perdic.Add(per.Name,per);
            }
            Person per6 =  perdic["s_6"];
            Console.WriteLine(per6.Scone);
        }
        class Person

        {
            public string Name;
            public int Scone;   
        }

x++ x-- 后置自增 后置自减

int x = 100;
            x++;
            //可以理解为 x=x+1;
            Console.WriteLine(x);

 int x = 100;
            int y = x++;
            //相当于 y=x;x=x+1;
            Console.WriteLine(x);
            Console.WriteLine(y);

typeof default 查看一个类型的内部结构

//Metadata

 static void Main(string[] args)
        {
            Type t = typeof(int);
            Console.WriteLine(t.Namespace);//名称空间
            Console.WriteLine(t.FullName);//全称
            Console.WriteLine(t.Name);
            int c = t.GetMembers().Length;
            foreach (var mi in t.GetMembers())
            {
                Console.WriteLine(mi.Name);
            }
            Console.WriteLine(c);
        }

new 在内存中创建一个实例，立即调用实例构造器

还能调用初始化器

Form myForm=new Form(){Text="Hello"}.ShowDialog();

var 声明一个隐式变量，类型确定了，就不能换类型；

var person = new { Name = "Mr.Okay", Age = "34" };
            Console.WriteLine(person.Name);
            Console.WriteLine(person.Age);
            Console.WriteLine(person.GetType().Name);

checked unchecked

 static void Main(string[] args)
        {
            //无符号整形 32位
            uint x = uint.MaxValue;
            Console.WriteLine(x);
            string binStr = Convert.ToString(x, 2);
            Console.WriteLine(binStr);
            uint y = x + 1;
            Console.WriteLine(y);
            try
            {
                uint y1 = checked(x + 1);
            }
            catch (OverflowException ex)
            { Console.WriteLine("溢出"); }
        }

delegate