2017-2-24 C#基础 for循环的嵌套

用几个练习题演示一下for循环的嵌套

1、打印以下图形

★
★★
★★★
★★★★
★★★★★

namespace _2017_2_24_for循环的嵌套
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入一个数字：");
            int a=Convert.ToInt32(Console.ReadLine());
            for (int i = ; i <= a;i++ )
            {
                for (int b = ; b <= i;b++ )
                {
                    Console.Write("★");
                }
                Console.Write("\n");
            }

            Console.ReadLine();
        }
    }
}

★★★★★
★★★★
★★★
★★
★

namespace _2017_2_24_for循环的嵌套_画星星2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入数字");

            int a = Convert.ToInt32(Console.ReadLine());
            for (int b = ; b <= a;b++ )
            {
                for (int c =a; c >= b;c-- )
                {
                    Console.Write("★");
                }
                Console.Write("\n");
            }
            Console.ReadLine();
        }
    }
}

○○○○★
○○○★★
○○★★★
○★★★★
★★★★★

namespace _2017_2_24_for循环的嵌套__画星星3
{
    class Program
    {
        static void Main(string[] args)
        {

            Console.WriteLine("请输入一个数字");
            int count = Convert.ToInt32(Console.ReadLine());
            String b = "  "; String c = "※"; 

            for (int d = ; d <= count; d++)
                {

                    for (int e = count - ; e >= d; e--)
                    {

                        Console.Write(b);
                    }

                    Console.Write(c);
                    for (int x = ; x < d-; x++)
                    {
                        Console.Write(c);
                    }

                        Console.Write("\n");

            }
            Console.ReadLine();
        }
    }
}

★★★★★
　★★★★
　　★★★
　　　★★
　　　　★

namespace _2017_2_24_for_循环_的嵌套__画星星4
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入一个数字：");
           int a=Convert.ToInt32( Console.ReadLine());
            String b="  ";String c="☆";
            for (int d = ; d <= a; d++)
            {

                for (int e = ; e < d;e++ )
                {
                    Console.Write(b);

                }

                for (int f = a-d; f <= a&&f>=; f--)
                {

                    Console.Write(c);
                }
                Console.Write("\n");

            }

            Console.ReadLine();
        }
    }
}

　　　　★
　　　★★★
　　★★★★★
　★★★★★★★
★★★★★★★★★
　★★★★★★★
　　★★★★★
　　　★★★
　　　　★

namespace _2017_2_24__for循环的嵌套___打印菱形
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入一个数字：");
            int a = Convert.ToInt32(Console.ReadLine());
            String b="○";String c="★";
            for (int d = ; d <= a;d++ )
            {
                for (int e = a - ; e >= d ;e-- )
                {
                    Console.Write(b);
                }
                for (int f = ; f <=(d * -);f++ )
                {
                    Console.Write(c);
                }
                Console.Write("\n");
            }
            for (int g = ; g < a;g++ )
            {
                for (int h = ; h <= g;h++ )
                {
                    Console.Write(b);
                }
                for (int i =; i <=( (a-g) * - );i++ )
                {
                    Console.Write(c);
                }
                Console.Write('\n');
            }
            Console.ReadLine();
        }
    }
}

用for循环嵌套编九九乘法表；

namespace _2017_2_24__for循环___九九乘法表
{
    class Program
    {
        static void Main(string[] args)
        {
            for (int a = ; a <= ;a++ )
            {
                for (int b = ; b <= a;b++ )
                {
                    Console.Write(a+"*"+b+"="+(a*b)+"\t");
                }
                Console.Write("\n");
            }
            Console.ReadLine();
        }
    }
}