Answer to Question #269338 in C# for lein

Question

If we change the integer argument of the call method for Fact into 10, what happens? Explain your answer

Answer 1

Integer type is value type, so when we pass it to some method as argument, it will copy just a value, but no a reference. It means that any changes inside the method will not affect real value that was passed. To change value-type into the method we have to use ref/out keywords.

 static void Main(string[] args)
        {
            int someValue = 20;
            ChangeSomething(someValue);
            Console.WriteLine($"Value = {someValue}"); //20


            ChangeSomething(ref someValue);
            Console.WriteLine($"Value = {someValue}"); //10


            Console.ReadLine();
        }




        public static void ChangeSomething(int value)
        {
            value = 10;
        }


        public static void ChangeSomething(ref int value)
        {
            value = 10;
        }