using System;
public class FunctionDemo {

  public static void Main (){
    ParameterPassing();
  }

  public static void ValueFunction(double d){
    d++;}

  public static void RefFunction(ref double d){
    d++;}

  public static void OutFunction(out double d){
    d = 8.0;}

  public static void ParamsFunction(out double res, 
                                    params double[] input){
    res = 0;
    foreach(double d in input) res += d;
  }

  public static void ParameterPassing(){
    double myVar1 = 5.0;
    ValueFunction(myVar1);
    Console.WriteLine("myVar1: {0:f}", myVar1);            // 5.00

    double myVar2 = 6.0;
    RefFunction(ref myVar2);
    Console.WriteLine("myVar2: {0:f}", myVar2);            // 7.00

    double myVar3; 
    OutFunction(out myVar3);
    Console.WriteLine("myVar3: {0:f}", myVar3);            // 8.00

    double myVar4;
    ParamsFunction(out myVar4, 1.1, 2.2, 3.3, 4.4, 5.5);  // 16.50
    Console.WriteLine("Sum in myVar4: {0:f}", myVar4);
  }

}