const和readonly的区别

 

class Program1

{

    public const string name = "小明";

private static readonly string age;

private static string sex;

//readonly是运行常量

private readonly string address = new string("中国广东");

//const是编译常量不能用new初始化

//private const string telphone = new string("123456");

 

    public Program1()

    {

        sex = "男";

        //static readonly只能声明时或静态构造函数中初始化

        //age = "23";   

}

 

    public void Fun()

{

    //const可以声明局部变量

        const int data = 90;   

        //readonly不可以声明局部变量

        //readonly int data1 = 80; 

}

}

 

class Program2

{

    static void Main()

    {

        Program1 p = new Program1();

        //const字段是静态的可以通过类名访问

        Console.WriteLine(Program1.name);   

       //const字段不能通过对象实例访问

       //Console.WriteLine(p.name);   

}

}