C# 数组

数组：具有相同类型的若干变量按有序的形式组织起来的一种形式。这些按序排列的同类数据元素的集合称为数组。

一维数组【相同数据类型】
第一种定义方式

int[] shuzu = new int[5];
for (int i = 0; i < 5; i++)
{
shuzu[i] = i + 1;
}
//索引从0开始
//赋值
//shuzu[0] = 1;
//shuzu[1] = 2;

//shuzu[2] = 3;
//shuzu[3] = 4;
//shuzu[4] = 5;
////shuzu[5] = 6;
////shuzu[6] = 7;
Console.WriteLine(shuzu[4]);

第二种定义方式

int[] shuzu = new int[] { 1,2,3,4,5 };
Console.WriteLine(shuzu[2]);

二维数组

int[,] shuzu = new int[3, 4];
int[,] shuzu = new int[,] {
{1,2,3,4},
{5,6,7,8},
{6,7,8,9}
};

string[,] shuzu = new string[,] {
{"  ","■","■","■","■","■",""},
{"  ","  ","  ","■","","",""},
{"  ","  ","  ","■","","",""},
{"  ","  ","■","■","■","",""},
{"  ","  ","  ","■","  ","  ",""},
{"  ","  ","  ","■","  ","  ",""},
{"■","■","■","■","■","■","■"}
};

for (int i = 0; i < 7; i++)
{
for (int j = 0; j < 7; j++)
{
Console.Write(shuzu[i, j]);
}
Console.WriteLine();
}

三维数组

int[, ,] shuzu = new int[3, 2, 4];
{
{
{,,,},
{,,,}
},
{
{,,,},
{,,,}
},
{

{,,,},
{,,,}
}
};

foreach不仅可以应用于数组，还可以应用于集合

//foreach遍历数组中各个元素，执行内部语句
foreach(double d in fen)
{

d是数组里面的元素的代表，从第一个元素开始遍历
Console.WriteLine(d);
}

object 所有类的基类，可以接受任何数据类型

foreach (int a in shuzu)//遍历数组
//object在不知道是什么数据类型时使用，代替现在int的位置
{
Console.WriteLine(a);
}

object a = 1;
object b = "123";
object c = true;
object d = 3.14;

一维数组练习

从控制台输入10个人的年龄放入数组，
将十个人的年龄求总和

int [] age=new int [10];
int sum = 0;
for (int i = 0; i < 10; i++)
{
Console.Write("请输入第"+(i+1)+"个人的年龄：");
age[i] = int.Parse(Console.ReadLine());
sum += age[i];
}
Console.WriteLine(sum);

输入人名放进数组，输出第5个人的姓名

Console.Write("请输入有几个人：");
int a = int.Parse(Console.ReadLine());
string [] name =new string [a];
for (int i = 0; i < a;i++ )
{
Console.Write("请输入第" + (i + 1) + "个人的姓名：");
name[i] = Console.ReadLine();
}
Console.WriteLine(name[4]);

输入班级人数，根据人数，
挨个输入成绩，求平均分

Console.Write("请输入班级人数：");
int a = int.Parse(Console.ReadLine());
double [] fen = new double [a];
double sum = 0;
for (int i = 0; i < a;i++ )
{
Console.Write("请输入第"+(i+1)+"个人的分数：");
fen[i] = double.Parse(Console.ReadLine());
sum += fen[i];
}
Console.WriteLine("班级平均分为："+sum/a);

冒泡排序 从大到小排列

int[] shuzu = new int[] { 3,1,8,4,0,5,6};
int zhong;
for (int i = 0; i < 7; i++)
{
for (int j = i; i < 6; j++)
{
if (shuzu[i] < shuzu[j + 1])
{
zhong = shuzu[i];
shuzu[i]=shuzu[j+1];
shuzu[j+1] = zhong;
}
}
}
for (int i=0; i<7; i++)
{
Console.WriteLine(shuzu[i]);
}

二维数组练习

输入班级人数，将每个人的
语文，数学，英语成绩输入二维数组

Console.Write("请输入班级人数：");
int a = int.Parse(Console.ReadLine());
double [,] shuzu = new double [a,3];

for (int i = 0; i < a; i++)
{
for (int j = 0; j < 3; j++)
{
if (j == 0)
{
Console.Write("请输入第"+(i+1)+"个人的语文成绩：");
}
if (j == 1)
{
Console.Write("请输入第" + (i + 1) + "个人的数学成绩：");
}

if (j == 2)
{
Console.Write("请输入第" + (i + 1) + "个人的英语成绩：");
}
shuzu[i, j] = double.Parse(Console.ReadLine());
}
}

冒泡排序和数组结合练习

输入人数，输入每个人的成绩
需要最高分，最低分
去掉两个最高分，去掉两个最低分，求平均分

Console.Write("请输入班级人数：");
int a = int.Parse(Console.ReadLine());
double[]fen=new double [a];
for (int i = 0; i <a; i++)
{
Console.Write("请输入第"+(i+1)+"个人的成绩");
fen[i] = double.Parse(Console.ReadLine());
}
double zhong;
for (int i = 0; i < a; i++)

{
for (int j = i; j< a-1; j++)
{
if (fen[i] < fen[j + 1])
{
zhong = fen[i];
fen[i] = fen[j + 1];
fen[j + 1] = zhong;
}
}
}

Console.WriteLine("最高分是"+fen[0]);
Console.WriteLine("最低分是"+fen[a-1]);
double sum = 0;
for (int i=2;i<a-2 ;i++ )
{
sum +=fen[i];
}
Console.WriteLine("平均分是"+sum/(a-4));

抽奖活动：
输入n个手机号码，滚动号码，5秒钟后停止
输出中奖人号码

Console.Write("请输入手机号码个数：");
int a = int.Parse(Console.ReadLine());
string [] shuzu = new string [a];
for (int i = 0; i < a; i++)
{
Console.Write("请输入第"+(i+1)+"个手机号码：");
shuzu[i] = Console.ReadLine();
}
Console.WriteLine("所有号码输入完毕，请按回车键开始滚动号码！");
Console.ReadLine();
Random ran = new Random();
int r = 0;
for (; ;)
{
int aa = ran.Next(a);
Console.Clear();
Console.WriteLine(shuzu[aa]);
System.Threading.Thread.Sleep(100);

if (r == 49)
{
//作弊代码
//Console.Clear();
//Console.WriteLine("110");
break;
}
r++;
}