C# 1116 流程控制 常量

常量

            //常量//不能修改，运行时//constconst int achang = 12;const double paichang = 3.14;const char cchang= 'F';int achang1 = achang + 2;int bchang1 = 22;double abchang = paichang * bchang1;Console.WriteLine("achang=" + achang + ",achang1=" + achang1+ ",abchang=" + abchang);

浮点常量

 //整数常量//八进制 十进制 十六进制//浮点常量const double pi = 3.14;const double afudianc = 3e3;//指数形式 修正 double bfudianc = afudianc * 4;const float cfudiancf = 1.2224f;Console.WriteLine("bfudianc:=\'"+bfudianc+"\',cfidianc:\'"+cfudiancf+"\'");

字符常量

//字符常量
const char czifu= 'a';const char dzifu = '\t';Console.WriteLine("优酷:\twww.mycraft.com\r\n");Console.WriteLine(czifu + "," + dzifu + "\\?"+"\\211"+"\r\n");

字符串常量

  //字符串常量const string wangzhan = "www.mycraft.com";const string zifuc = @"ssadas";Console.WriteLine("wangzhan:\'" + wangzhan + "\',zifuchaun:" + zifuc);

流程控制

if

namespace LiuChenPanDuan
{internal class Program{static void Main(string[] args){int age = 11;if (age == 18) { Console.WriteLine("you are too y"); }else { Console.WriteLine("AGE:"+age); }age++;Console.WriteLine("Hello, World!");}}
}

   decimal price = 1399.5m;if (price > 1000){Console.WriteLine("price too high");} else {Console.WriteLine("price is normal");
}

  //if else ifConsole.WriteLine("Please input the price");int priceCs = Convert.ToInt32(Console.ReadLine());if (priceCs < 0) {Console.WriteLine("wrong");}else if (priceCs >= 0 && priceCs < 200) {Console.WriteLine("you cannot buy anything");}else if (priceCs >=200 && priceCs <2000){Console.WriteLine("you can buy gun,like use or " +"can buy smoke,flash..or clothes");}else if(priceCs >=2000 ){Console.WriteLine("YOU can buy exllent gun,like p90");}

switch

   //switchConsole.WriteLine("Pl input a name");string rename = Console.ReadLine();switch (rename){case "siye":Console.WriteLine("classroom");break;case "faker":Console.WriteLine("god");break;case "":Console.WriteLine("5555");break;default:Console.WriteLine("A NAME");break;}Console.WriteLine("PL input a count");int count = 3;switch (count){case 1:Console.WriteLine("exllent"); break;case 2:Console.WriteLine("wonderful"); break;case 3:Console.WriteLine("god"); break;}

for

进行条件判断，如果为 true，则执行循环主体，如果为假，则跳出 for 循环，

    //for循环Console.WriteLine("pl input a str,str.length have to >5");string str1=Console.ReadLine();if (str1.Length < 5) { Console.WriteLine("str.length<5");return;}for (int i = str1.Length; i > 5; i--){Console.WriteLine(str1[i-1]);str1 = "0" + str1;}Console.WriteLine(str1);}

    Console.WriteLine(str1);string str2 = Console.ReadLine();for(int i=str2.Length; i < 5; i++){str2 = "1" + str2;}Console.WriteLine(str2);
}

 Console.WriteLine(str2);string str3 = Console.ReadLine();for (int i = 0; i < str3.Length; i++){if (i > 0 && i < str3.Length){ Console.WriteLine(""); }Console.WriteLine(str3[i]);}

乘法表

 //for 嵌套for (int i = 1; i <= 9; i++){ for(int j = 1; j <= i; j++){int reu = i * j;string result = reu.ToString().Length == 1 ? reu + "" : reu.ToString();Console.Write("{0}x{1}={2}",j,i,result);}Console.WriteLine();

无限循环

//无限循环
for (int i = 0;;i++)
{if (i < 10){Console.WriteLine("执行中");}elsebreak;
}

            int j1 = 0;for (int i = 0; ; i++){ j1++; }

 string[] names = new string[] { "lk", "kok", "ln", "li" };foreach (string name in names){Console.WriteLine("{0}", name);}

while

  //whileint iw = 1;int sum = 0;while (iw <= 100){sum = sum + iw;iw++;}Console.WriteLine("1到100的和是:"+sum);

            int i9 = 1;while (i9 <= 9){int j9 = 1;while (j9 <= i9){int res = i9 * j9;string result = res.ToString().Length==1?res+"":res.ToString();//字符串1的长度为1吗？14长度为2吗 这里就是格式上个位（一位数）和两位数对齐吗？//是Console.Write("{0} x {1}={2}", j9, i9, result);j9++;
}i9++;Console.WriteLine();      }

do while

 //do whileint doi = 1;int dosum = 0;do{dosum += doi;doi++;} while (doi <= 5);Console.WriteLine("dosum:"+dosum);int do9i = 1;

   int do9i = 1;do{int do9j = 1;do{int resdo = do9i * do9j;string resultdo = resdo.ToString().Length == 1 ? resdo + "" : resdo.ToString();Console.Write("{0} x {1} = {2} " ,do9i,do9j,resultdo);} while (do9j <= do9i);do9i++;Console.WriteLine();} while (do9i <= 9);

 int do9i = 1;do{int do9j = 1;do{int resdo = do9i * do9j;string resultdo = resdo.ToString().Length == 1 ? resdo + "" : resdo.ToString();Console.Write("{0} x {1} = {2} " ,do9i,do9j,resultdo);do9j++;} while (do9j <= do9i);do9i++;Console.WriteLine();} while (do9i <= 9);

break

直接跳出循环
1+…4

  int sumb = 0;for (int i = 0; i < 10; i++){if (i == 5)break;sumb += i;}

continue

1+…4 +6+…9
跳过余数是5的循环

  //continueint sumc= 0;for(int i = 0;i < 10; i++){if (i%5==0){continue;}sumc += i;            }Console.WriteLine("sumc:"+sumc);