C#抽象属性

using System;
namespace jb51.cc {
   public abstract class Person {
      public abstract string Name {
         get;
         set;
      }
      public abstract int Age {
         get;
         set;
      }
   }

   class Student : Person {

      private string code = N.A;
      private string name = N.A;
      private int age = 0;

      // Declare a Code property of type string:
      public string Code {
         get {
            return code;
         }
         set {
            code = value;
         }
      }

      // Declare a Name property of type string:
      public override string Name {
         get {
            return name;
         }
         set {
            name = value;
         }
      }

      // Declare a Age property of type int:
      public override int Age {
         get {
            return age;
         }
         set {
            age = value;
         }
      }
      public override string ToString() {
         return Code =  + Code +, Name =  + Name + , Age =  + Age;
      }
   }

   class ExampleDemo {
      public static void Main() {
         // Create a new Student object:
         Student s = new Student();

         // Setting code, name and the age of the student
         s.Code = 001;
         s.Name = Zara;
         s.Age = 9;
         Console.WriteLine(Student Info:- {0}, s);

         //let us increase age
         s.Age += 1;
         Console.WriteLine(Student Info:- {0}, s);
         Console.ReadKey();
      }
   }
}