学步园

 int i = 1, oddsum = 0;
            for (; i <= 100; i+=2)
            {
                oddsum += i;
            }
            Console.WriteLine(oddsum);//1-100奇数求和


            int[] nums ={12,34,11,56,77,79,35};
            int odd=0,even=0;
            foreach(int k in nums)
            {
                if (k % 2 == 0)
                    odd++;
                else even++;
            }
            Console.WriteLine(odd);//数组奇数个数
            Console.WriteLine(even);//数组偶数个数