using System;
public class bijiao
{
    private double[] a = new double[10];
    private double[] b = new double[10];

    public bijiao()
    {
        Console.WriteLine("请输入数组a的值");
        for (int i = 0; i <= 9; i++)
        {
            Console.WriteLine("a[" + i + "]=");
            a[i] = double.Parse(Console.ReadLine());
        }
        Console.WriteLine("请输入数组b的值");
        for (int k = 0; k <= 9; k++)
        {
            Console.WriteLine("b[" + k + "]=");
            b[k] = double.Parse(Console.ReadLine());
        }
      
    }
    void fangfa()
    {
        String str = "";
        if (a[i] == b[k])
        {
            str = string.Format("a[" + i + "]=b[" + k + "]={0}", a[i]);
            Console.WriteLine(str);
        }     
    }
  public static void Main()
    {
        bijiao b1 = new bijiao();
        b1.fangfa();
    }
}

    public class bijiao
    {
        private double[] a = new double[10];
        private double[] b = new double[10];
       
        int i, k;

        public bijiao()
        {
            Console.WriteLine("请输入数组a的值");
            for (i = 0; i <= 9; i++)
            {
                Console.WriteLine("a[" + i + "]=");
                a[i] = double.Parse(Console.ReadLine());
            }
            Console.WriteLine("请输入数组b的值");
            for (k = 0; k <= 9; k++)
            {
                Console.WriteLine("b[" + k + "]=");
                b[k] = double.Parse(Console.ReadLine());
            }

        }

        void fangfa(int i, int k)
        {
            String str = "";
            if (a[i] == b[k])
            {
                str = string.Format("a[" + i + "]=b[" + k + "]={0}", a[i]);
                Console.WriteLine(str);
            }
        }
        public static void Main()
        {
            bijiao b1 = new bijiao();
            b1.fangfa(b1.i, b1.k);
        }
    }

不过，这段代码有啥意思呢，i 和 k 的值肯定都是10啊,而且运行到　if (a[i] == b[k])　肯定是要出错的

using System;
public class bijiao
{
    private double[] a = new double[10];
    private double[] b = new double[10];
    int i = 0, k = 0;
    public bijiao()
    {
        Console.WriteLine("请输入数组a的值");
        for (int i = 0; i <= 9; i++)
        {
            Console.WriteLine("a[" + i + "]=");
            a[i] = double.Parse(Console.ReadLine());
        }
        Console.WriteLine("请输入数组b的值");
        for (int k = 0; k <= 9; k++)
        {
            Console.WriteLine("b[" + k + "]=");
            b[k] = double.Parse(Console.ReadLine());
        }

    }
    void fangfa()
    {
        String str = "";
        for (int i = 0; i <= 2; i++)
        {
            for (int k = 0; k <= 2; k++)
                if (a[i] == b[k])
                {
                    str = string.Format("a[" + i + "]=b[" + k + "]={0}", a[i]);
                    Console.WriteLine(str);
                }
        }
    }
    public static void Main()
    {
        bijiao b1 = new bijiao();
        b1.fangfa();
        Console.ReadLine();
    }
}
就是这样子啦！！！

没有结果呀 大哥！！！！！！！！

谢了！！！！！！！！！！1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        public class bijiao
        {
            private double[] a = new double[10];
            private double[] b = new double[10];

            public bijiao()
            {
                Console.WriteLine("请输入数组a的值");
                for (int i = 0; i <= 9; i++)
                {
                    Console.Write("a[" + i + "]=");
                    a[i] = double.Parse(Console.ReadLine());
                }
                Console.WriteLine("请输入数组b的值");
                for (int k = 0; k <= 9; k++)
                {
                    Console.Write("b[" + k + "]=");
                    b[k] = double.Parse(Console.ReadLine());
                }

            }
         public    void fangfa()
            {
                String str;
                for (int i=0;i<=9;i++)
                if (a[i] == b[i])
                {
                    str = string.Format("a[" + i + "]=b[" + i + "]={0}", a[i]);
                    Console.WriteLine(str);
                }
            }
            static void Main(string[] args)
            {
                bijiao b1 = new bijiao();
                b1.fangfa();


            }

        }
    }
}

怎么会没结果呢，我可是调试过的阿