c#---ref參數

員工基本工資為5000元，獎金方法+500元，調用該方法之后為什么工資還是5000元？

static void Main(string[] args)
        {
            double salary = 5000;
            jiangJin(salary);
            Console.WriteLine(salary);
            Console.ReadKey();
        }

        public static void jiangJin(double salary)
        {
            salary += 500;
        }

5500的正確代碼寫法，是不是有點麻煩呢？

static void Main(string[] args)
        {
            double salary = 5000;
            double d = jiangJin(salary);
            Console.WriteLine(d);
            Console.ReadKey();
        }

        public static double jiangJin(double salary)
        {
            salary += 500;
            return salary;
        }

ref參數：將變量帶入一個方法中改變之后在帶出方法

注意事項：

ref參數在方法外也就是調用方法之前必須為其賦值

 static void Main(string[] args)
        {
            double salary = 5000;
            jiangJin(ref salary);
            Console.WriteLine(salary);
            Console.ReadKey();
        }
        public static void jiangJin(ref double salary)
        {
            salary += 500;

        }

ref參數在變量交換中的示例

 static void Main(string[] args)
        {
            int n1 = 10;
            int n2 = 100;
            Program.Test(ref n1, ref n2);
            Console.WriteLine(n1);
            Console.WriteLine(n2);
            Console.ReadKey();
        }

        public static void Test(ref int n1, ref int n2)
        {
            int temp = n1;
            n1 = n2;
            n2 = temp;
        }