using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._1_分支语句之if语句
{
class Program
{
static void Main(string[] args)
{
//判断变量a中存放数值与10的关系
Console.WriteLine("请输入数值，判断它与10的关系：");
int a = int.Parse(Console.ReadLine());
//int.Parse用于将屏幕输入的语句转换为整型
if (a<10)
{
Console.WriteLine("您输入的数什小于10");
}
else if (a==10)
{
Console.WriteLine("您输入的数值等于10");
}
else//如果前边的if语句一条也没有执行，那就执行else语句
//如果执行了其中一条if句语，那就不会执行else语句
{
Console.WriteLine("您输入的数值大于10");
}
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._2_分支语句之switch语句
{
class Program
{
static void Main(string[] args)
{
//输入1显示星期一，依次类推
Console.WriteLine("请输入月分数");
int month = int.Parse(Console.ReadLine());
//if (week == 1) Console.WriteLine("星期一");
//if (week == 2) Console.WriteLine("星期二");
//if (week == 3) Console.WriteLine("星期三");
//if (week == 4) Console.WriteLine("星期四");
//if (week == 5) Console.WriteLine("星期五");
//if (week == 6) Console.WriteLine("星期六");
//if (week == 7) Console.WriteLine("星期日");
//switch (week)
//{
// case 1: Console.WriteLine("星期一"); break;
// case 2: Console.WriteLine("星期二"); break;
// case 3: Console.WriteLine("星期三"); break;
// case 4: Console.WriteLine("星期四"); break;
// case 5: Console.WriteLine("星期五"); break;
// case 6: Console.WriteLine("星期六"); break;
// case 7: Console.WriteLine("星期日"); break;
// default: Console.WriteLine("您的输入有误"); break;
//}
//判断2015年每个月份的天数
//31天：1、3、5、7、8、10、12
//30天：4、6、9、11
//28天：2
switch(month)
{
case 2: Console.WriteLine("本月有28天");break;
case 4:
case 6:
case 9:
case 11:
Console.WriteLine("本月有30天");break;
default: Console.WriteLine("本月有31天");break;
}
Console.ReadLine();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._3分支语句之三元运算符
{
class Program
{
static void Main(string[] args)
{
//提示用户进行输入
Console.WriteLine("请输入您需要比较的数值");
int num = int.Parse(Console.ReadLine());
Console.WriteLine(num < 10 ? "您输入的数值小于10" : "您输入的数值大于等于10");
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._4_迭代语句之while语句
{
class Program
{
static void Main(string[] args)
{
//输出1-50到屏幕上
//Console.WriteLine(1);
//Console.WriteLine(2);
//Console.WriteLine(3);
//利用while可以大量简化重复执行的代码
int num = 1;
while (num <= 50)
{
Console.WriteLine(num);
num++;
}
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._5_迭代语句之do._.while语句
{
class Program
{
static void Main(string[] args)
{
//输出1-50到屏幕上
//int num = 0;
//do
//{
// num++;
// Console.WriteLine(num);
//} while (num !=0);
double Balance=0;
double Rate = 0;
int Year = 0;
double TargetBalance = 0;
Console.WriteLine("请输入您的本金");
Balance = double.Parse(Console.ReadLine());
Console.WriteLine("请输入当前的利率百分比");
Rate = double.Parse(Console.ReadLine())/100;
Console.WriteLine("请输入您的目标收益");
//验证输入的有效性
do
{
TargetBalance = double.Parse(Console.ReadLine());
if (TargetBalance <= Balance) Console.WriteLine("您没有必要存钱，请重新输入一个比本金大的收益");
} while (TargetBalance<=Balance);
do
{
Balance *= (Rate+1);
Year++;
} while (Balance<TargetBalance);
Console.WriteLine("您将在{0}年内，获得{1}元的收益",Year,Balance);
Console.ReadLine();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._6_迭代语句之for循环语句
{
class Program
{
static void Main(string[] args)
{
//求输入数的阶乘
//1！＝1 2!=2×1 3！＝3×2×1
//Console.WriteLine("请输入需要计算阶乘的数");
//for(;;)
//{
//int a =int.Parse(Console.ReadLine());
//int jc = 1;
//for (int i=1;i<=a;i++)
//{
// jc *= i;
//}
//Console.WriteLine("阶乘的结果是"+jc);
Console.WriteLine("＝＝＝＝＝＝＝＝＝＝＝＝＝＝九九乘法表＝＝＝＝＝＝＝＝＝＝＝＝");
for (int i = 1; i < 10; i++)
{
for (int j = 1; j <= i; j++)
{
Console.Write("{0}×{1}＝{2} ", j, i, j * i);
if (i * j < 10) Console.Write(" ");
}
Console.WriteLine();
}
Console.ReadLine();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._7_迭代语句之for循环语句_2_
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("=====================九九乘法表=====================");
//使用for循环时，一般在for循环语句进行声明循环计次的变量
for (int i = 1; i < 10; i++)
{
for (int j = 1; j <= i; j++)
{
Console.Write("{0}×{1}＝{2} ",j,i,j*i);
if (i * j < 10) Console.Write(" ");
}
Console.WriteLine();
}
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._8_迭代语句之foreach语句
{
class Program
{
static void Main(string[] args)
{
//for (int i = 1; i <= 50; i++)
//{
// Console.WriteLine(i);
//}
//for (int i = 0; i < =50; i++)
//{
// Console.WriteLine(i);
//}
//将语句识别为单词并逐行输出
//语句用string类型 字母用char
Console.WriteLine("请您输入一个英文句子");
string str = Console.ReadLine();
Console.WriteLine("您输入的句子包含以下的单词");
foreach (char word in str)
{
if (char.IsWhiteSpace(word))
{
Console.WriteLine();
}
else
{
Console.Write(word);
//word = 't';//foreach语句的迭代变量不允许重新赋值
}
}
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._9_跳转语句之break语句
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("输出1-500的数字，每行10个");
for (int i = 1; i < 501; i++)
{
if ((i % 2 == 0) && (i % 3 == 0) && (i % 4 == 0) && (i % 5 == 0) && (i % 6 == 0) && (i % 7 == 0))
{
Console.Write(i);
Console.WriteLine();
Console.WriteLine(i+"就是我们想要的那个数");
break;
}
if (i % 10 == 0) Console.WriteLine(i);
else
{
Console.Write(i+" ");
if (i < 10) Console.Write(" ");
if (i < 100) Console.Write(" ");
}
}
Console.ReadLine();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._10_跳转语句之continue语句
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("50以内的奇数有：");
for (int i = 1; i < 51; i++)
{
if (i % 2 == 0) continue;
//continue语句用于停止本次迭代，并非跳出迭代语句
Console.Write(i+"\t");
}
Console.ReadLine();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._11_跳转语句之return语句
{
class Program
{
static void Main(string[] args)
{
while(true)
{
Console.WriteLine("请输入三个整数，按回车键确认每个数的输入：");
int a = int.Parse(Console.ReadLine());
int b = int.Parse(Console.ReadLine());
int c = int.Parse(Console.ReadLine());
average(a,b,c);
//double average = (a+b+c)/3;
//double Average = average(a,b,c);
//Console.ReadLine();
}
}
static void average(int a, int b, int c)
{
Console.WriteLine("您输入三个整数的平均值是：{0}", (a + b + c) / 3);
return ;
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._12_跳转语句之goto语句
{
class Program
{
static void Main(string[] args)
{
int a = 0;
Console.WriteLine("5的阶乘等于几？根据以下选项选择正确答案，回车键确认：");
Console.WriteLine("1. 5!=5\n2. 5!=10\n3. 5!=20\n4. 5!=60");
error:
{
a++;
if (a > 1) Console.WriteLine("很遗憾,您答错了,请重新输入答案.");
}
int option = int.Parse(Console.ReadLine());
switch (option)
{
case 1:
case 2:
case 3: goto error;
case 4:goto right;
default:
Console.WriteLine("您选择的选项不存在");
goto end;
}
right:
Console.WriteLine("恭喜您，答对了！");
end:
Console.ReadKey();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _5._13_本章小结及任务实施
{
class Program
{
static void Main(string[] args)
{
while(true)
{
Console.WriteLine("请输入三个整数，我们将给您算出中间数和它的阶乘");
int a = int.Parse(Console.ReadLine());
int b = Convert.ToInt32(Console.ReadLine());
int c = int.Parse(Console.ReadLine());
int middleNum = 0;
//a是中间值，那么有两种情况，b是最小值或都b是最大值
//b
//c
if (a >= b && a <= c || a >= c && a <= b)
{
Console.WriteLine(a + "是中间值");
middleNum = a;
}
if (b >= a && b <= c || b >= c && b <= a)
{
Console.WriteLine(b + "是中间值");
middleNum = b;
}
if (c >= a && c <= b || c >= b && c <= a)
{
Console.WriteLine(c + "是中间值");
middleNum = c;
}
int result = 1;
for (int i = 1; i <= middleNum; i++)
{
result *= i;
}
Console.WriteLine("它的阶乘是" + result);
}
Console.ReadKey();
}
}
}
