C#基础

    class Program
    {
        static void Main(string[] args)
        {
            #region 交换两个变量
            /*
            int num1 = 10;
            int num2 = 20;

            //1、声明第三个变量
            int temp = num1;
            num1 = num2;
            num2 = temp;

            //2、不声明第三个变量，加减法(只能是数字)
            num1 = num1 + num2;
            num2 = num1 - num2;
            num1 = num1 - num2;


            Console.WriteLine("num1={0} , num2={1}", num1, num2);
            Console.ReadKey();
            */
            #endregion

            #region 求两个数的最大值
            /*
            int max = GetMaxVal(10, 20);

            Console.WriteLine(max);
            Console.ReadKey();
            */
            #endregion

            #region 求1-100之间所有奇数的和
            /*
            int sum = GetSum(100);

            Console.WriteLine(sum);
            Console.ReadKey();
            */
            #endregion

            #region 求数组中的最大值
            /*
            int[] array = new int[] { 10, 50, 30, 60, 80, 70, 40, 20, 90 };

            int max = GetMaxVal(array);

            Console.WriteLine(max);
            Console.ReadKey();
            */
            #endregion
        }

        /// <summary>
        /// 求数组中的最大值
        /// </summary>
        /// <param name="array">数组</param>
        /// <returns></returns>
        private static int GetMaxVal(int[] array)
        {
            int temp = array[0];
            for (int i = 0; i < array.Length; i++)
            {
                if (array[i] > temp)
                    temp = array[i];
            }
            return temp;
        }

        /// <summary>
        /// 求1到某个数之间所有奇数的和
        /// </summary>
        /// <param name="p"></param>
        /// <returns></returns>
        private static int GetSum(int p)
        {
            int sum = 0;
            for (int i = 0; i < 100; i++)
            {
                if (i % 2 != 0)
                {
                    sum += i;
                }
            }
            return sum;
        }

        /// <summary>
        /// 获取两个数的最大值
        /// </summary>
        /// <param name="p1">数值1</param>
        /// <param name="p2">数值2</param>
        /// <returns></returns>
        private static int GetMaxVal(int p1, int p2)
        {
            return p1 > p2 ? p1 : p2;
        }
    }