面向对象：封装、函数重载、静态变量、构造函数

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

namespace ConsoleApplication3
{
    class Class1
    {
        private string _name;

        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }
        private string _type;

        public string Type
        {
            get { return _type; }//取值
            set { _type = value; }//赋值
        }
        private string _food;

        public string Food
        {
            get { return _food; }
            set {
                if (value=="meat")
                    {
                       _food = "我吃肉！";
                    }
                else
                {
                    _food = "我不吃别的！";
                }
                
                }
        }
    }
}

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

namespace ConsoleApplication3
{
    class Class2//function 重载
    {
        public void function(string s)
        {
            Console.WriteLine(s);
        }
        public void function(string s,string s1)
        {
            Console.WriteLine(s+s1);
        }
    }
}

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

namespace ConsoleApplication3
{
    class Class3
    {
        /// <summary>
        /// 构造函数，每一个类至少有一个构造函数，函数名字与类名相同，并且没有返回值,下面的public不写也可以默认存在，构造函数也可以重载
        /// </summary>
        public Class3()
        {
 
        }

        public Class3(int a)
        {
            Num1 = a;
        }

        public int Num1;
        public static int Num2;//静态成员,不随着NEW造对象走
    }
}

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

namespace ConsoleApplication3
{
    class Class4
    {
        public Class4(string sname,string ssex,int sold) 
        {
            name = sname;
            sex = ssex;
            old = sold;
        }
        public string name;
        public string sex;
        public int old;
    }
}

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

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            Class1 s = new Class1();
            s.Food = "meat";
            s.Name = "tiger";
            s.Type = "less";
            Console.WriteLine(s.Food);//以上为封装




            Class2 data = new Class2();
            data.function("123");
            data.function("aaa"+"123");//函数重载

            


            Class3 data1 = new Class3();
            data1.Num1 = data1.Num1 + 3;//data1点不出Num2
            Class3.Num2 += 3;//不通过data1，直接通过Class调用
            Class3 data2 = new Class3();
            data2.Num1 = data2.Num1 + 3;
            Class3.Num2 += 3;//静态成员Num2不随着造对象走，Num2为3，3+3=6
            Console.WriteLine(Class3.Num2);//为6

            Class3 data4 = new Class3();//构造函数的重载
            Class3 data3 = new Class3(2);//构造函数的重载
            Console.WriteLine(data3.Num1);//构造函数结果为2，为某些成员变量赋初始值




            Class4 t1 = new Class4("张三", "男", 18);//用构造函数给变量赋初始值
            Class4 t2 = new Class4("李四", "女", 17);
            Console.WriteLine(t1.name+t1.old+t1.sex);

            Console.ReadLine();
        }
    }
}