01复习
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _01复习
{
class Program
{
static void Main(string[] args)
{
/*
字符串
* 1、字符串的不可变性
* 2、字符串的一坨方法：
* Split()
* Substring()
* ToUpper()
* ToLower()
* Trim()
* TrimEnd()
* TrimStart()
* Contains()
* Replace()
* IndexOf
* LastIndexof
* StartsWith
* EndsWith
* string.join()
* string.IsNullOrEmpty()
* ToCharArray()
* new string(char[] chs)
*
* 继承：解决类中的代码冗余
* 属性、方法、构造函数 子类默认调用父类无参数的构造函数
* this:
* base:
* new:
*
*
*
*
*/
}
}
}
02里氏转换
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _02里氏转换
{
class Program
{
static void Main(string[] args)
{
//// 1、里氏转换
////1)、子类可以赋值给父类:如果有一个地方需要一个父类作为参数，我们可以给一个子类代替
// Student s = new Student();
Person p = new Student();//s;
//string str = string.Join("|",new string[] { "1", "2", "3", "4" });
//Console.WriteLine(str);
//Console.ReadKey();
////2)、如果父类中装的是子类对象，那么可以讲这个父类强转为子类对象。
//is的用法
//if (p is Student)
//{
// Student ss = (Student)p;
// ss.StudentSayHello();
//}
//else
//{
// Console.WriteLine("转换失败");
//}
//as的用法
Student t = p as Student;
t.StudentSayHello();
Console.ReadKey();
}
}
public class Person
{
public void PersonSayHello()
{
Console.WriteLine("我是父类");
}
}
public class Student : Person
{
public void StudentSayHello()
{
Console.WriteLine("我是学生");
}
}
public class Teacher : Person
{
public void TeacherSayHello()
{
Console.WriteLine("我是老师");
}
}
}
03里氏转换练习
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _03里氏转换练习
{
class Program
{
static void Main(string[] args)
{
//创建10个对象 通过一个循环 去调用他们各自打招呼的方法
//Student s = new Student();
//Person p = new Person();
//ShuaiGuo sg = new ShuaiGuo();
Person[] pers = new Person[10];
Random r = new Random();
for (int i = 0; i < pers.Length; i++)
{
int rNumber = r.Next(1, 7);
switch (rNumber)//1-6
{
case 1: pers[i] = new Student();
break;
case 2: pers[i] = new Teacher();
break;
case 3: pers[i] = new ShuaiGuo();
break;
case 4: pers[i] = new MeiLv();
break;
case 5: pers[i] = new YeShou();
break;
case 6: pers[i] = new Person();
break;
}
}
for (int i = 0; i < pers.Length; i++)
{
// pers[i].PersonSayHi();
if (pers[i] is Student)
{
((Student)pers[i]).StudentSayHi();
// pers[i].PersonSayHi();
}
else if (pers[i] is Teacher)
{
((Teacher)pers[i]).TeacherSayHi();
}
else if (pers[i] is ShuaiGuo)
{
((ShuaiGuo)pers[i]).ShuaiGuoSayHi();
}
else if (pers[i] is YeShou)
{
((YeShou)pers[i]).YeShouSayHi();
}
else if (pers[i] is MeiLv)
{
((MeiLv)pers[i]).MeiLvSayHi();
}
else
{
pers[i].PersonSayHi();
}
}
Console.ReadKey();
}
}
public class Person
{
public void PersonSayHi()
{
Console.WriteLine("我是人类");
}
}
public class Student : Person
{
public void StudentSayHi()
{
Console.WriteLine("我是学生");
}
}
public class Teacher : Person
{
public void TeacherSayHi()
{
Console.WriteLine("我是老师");
}
}
public class MeiLv : Person
{
public void MeiLvSayHi()
{
Console.WriteLine("我是镁铝");
}
}
public class ShuaiGuo : Person
{
public void ShuaiGuoSayHi()
{
Console.WriteLine("我是帅锅");
}
}
public class YeShou : Person
{
public void YeShouSayHi()
{
Console.WriteLine("我是野兽");
}
}
}