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

namespace ConsoleApplication7
{
    class Program
    {
        static void Main(string[] args)
        {
            char[] a={'a','b','c','d','1','2','3'};
            foreach(char i in a)
            {
                int j;
                for (j= 0; j < 4; j++)
                {
                    a[j] = a[j] - 32;
                  
                }
                for (j = 0; i < 7; j++)
                {
                    Console.WriteLine();
                }
            }
        }
    }
}




新手不知道怎么做这个题目 ，求帮助

没有人么

还是有错误。。。