using System;
namespace class1
{
    class program
    {
        static void Main(string[] args)
        {
            //值传递引用，实际参数不会变化
            Console.Write("请输入a=");
            double a = double.Parse(Console.ReadLine());
            Console.Write("请输入b=");
            double b = double.Parse(Console.ReadLine());
            double c = max(a, b);//局部实际参数
            Console.WriteLine("您输入的值中比较大的是{0}", c);
            //地址传递引用，实际参数会变化
            int[] ex = new int[4] { 1, 2, 3, 4 };
            Console.WriteLine("Before");
            foreach (var item in ex)
            {
                Console.Write("\t{0}", item);
            }
            dou(ex);
            Console.WriteLine("\nEnd");
            foreach (var item in ex)
            {
                Console.Write("\t{0}", item);
            }
        }
        /// <summary>
        /// 值传递
        /// </summary>
        /// <param name="a">形式参数（参数为值类型）</param>
        /// <param name="b">形式参数（参数为值类型）</param>
        /// <returns></returns>
        static double max(double a, double b)
        {//局部形式参数
            double c = a > b ? a : b;
            return c;
        }
        /// <summary>
        /// 地址传递
        /// </summary>
        /// <param name="array">数组参数（参数为引用类型）</param>
        static void dou(int[] array)
        {
            for (int i = 0; i < array.Length; i++)
            {
                array[i] = array[i] * 2;
            }
        }
    }
}