for(初始条件；比较；状态改变 )
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循环体
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//打印100遍helloword
for(int i=0;i<100,i++)
{
console.writeline("helloword");
}
////求1-100的和
int s = 0;
for(int i=1;i<=100;i++)
{
s = s + i;
}
Console.WriteLine(s);
Console.ReadLine();
//100以内所有与7相关的数和，奇数和，偶数和
int s = 0;
for (int i = 1; i <= 100; i++)
{
if ((i % 7 == 0) || (i % 10 == 7) || (i / 10 == 7))
{
s = s + i;
}
}
Console.WriteLine(s);
Console.ReadLine();
//100以内的所有质数和
int sum = 0;
for (int i = 2; i <=100; i++)
{
int a = 0;
for (int j = 1; j <=i; j++)
{
if (i % j == 0)//如果i能被它本身和1以外的数整除，那么他就不是质数
{
a++;
}
}
if (a == 2) //能被整除的数只有两个，即为质数
{
sum = sum + i;
Console.Write(i + "\t");
}
}
Console.Write("和"+sum);
Console.ReadLine();
//打印☆，排列成图形
for (int m = 1; m < 10; m++)
{
for (int n = 1; n <= m; n++)
{
Console.Write("☆");
}
Console.Write("\n");
}
////右下
for (int m = 10; m > 1; m--)
{
for (int n = 1; n < m; n++)
{
Console.Write("☆");
}
Console.Write("\n");
}
////左下
for (int m = 1; m < 10; m++)
{
for (int n = 1; n < m; n++)
{
Console.Write(" ");
}
for (int l = 10; l > m; l--)
{
Console.Write("☆");
}
Console.Write("\n");
}
////左上
for (int m = 1; m < 10; m++)
{
for (int n = 9; n >m; n--)
{
Console.Write(" ");
}
for (int l = 1; l <= m;l++ )
{
Console.Write("☆");
}
Console.Write("\n");
}
//上半部分
for (int m = 1; m < 10; m++)
{
for (int n = 9; n > m; n--)
{
Console.Write(" ");
}
for (int l = 1; l <= (2 * m - 1); l++)
{
Console.Write("☆");
}
Console.Write("\n");
}
////下半部分
for (int m = 1; m < 9; m++)
{
for (int l = 1; l <= m; l++)
{
Console.Write(" ");
}
for (int n = 1; n <= (2 * (9 - m) - 1); n++)
{
Console.Write("☆");
}
Console.Write("\n");
}
for (int i = 2; i <= 24; i++)
{
if (i == 1)
{
c = 0;
b = 0;
a = 1;
}
else
{
c = c + b;
b = a;
a = c;
}
Console.WriteLine("第{0}个月,成兔数量:{1}小兔数量{2}:幼兔数量{3}", i, c, b, a);
Console.ReadLine();
}
Console.WriteLine("总数量为" + (c + a + b));
Console.ReadLine();
{
for (int he = 1; he <= 20; he++)
{
for (int wenjianjia = 1; wenjianjia <= 10; wenjianjia++)
{
for (int caibi = 1; caibi <= 7; caibi++)
{
int a = qianbi * 2 + he * 5 + wenjianjia * 10 + caibi * 15;
if (a == 100)
{
Console.WriteLine("铅笔买{0}只,盒买{1}个,文件夹买{2}个,彩笔买{3}支", qianbi, he, wenjianjia, caibi);
}
}
}
}
}
Console.ReadLine();