C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 类_继承
{
    // 基类 : 动物
    public abstract class Animal
    {
        private int _age;
        public int Age
        {
            get { return this._age; }
            set
            {
                if (value < 0 || value > 10)
                {
                    throw (new ArgumentOutOfRangeException("AgeIntPropery", value, "年龄必须在0-10岁之间"));
                }
                this._age = value;
            }
        }

        // virtual修饰基类的Print()方法, 在子类中 override重写 实现子类实际需求
        public virtual void Print()
        {
        }

    }

    // 子类 : 马  (继承基类 : Animal) 
    public class Horse : Animal
    {
        // 重写基类的Print()方法;
        public override void Print()
        {
            Console.WriteLine("马的年龄为 : {0} 岁", this.Age);
        }
    }

    // 子类 : 羊  (继承基类 : Animal) 
    public class Sheep : Animal
    {
        // 重写基类的Print()方法;
        public override void Print()
        {
            Console.WriteLine("羊的年龄为 : {0} 岁", this.Age);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Horse horse = new Horse();
            horse.Age = 2;
            horse.Print();

            Sheep sheep = new Sheep();
            sheep.Age = 9;
            sheep.Print();

            Console.ReadLine();
        }
    }
}