C# 7 and .NET Core: Modern Cross-Platform Development - Second Edition

Controlling how parameters are passed

When a parameter is passed into a method, it can be passed in one of three ways:

• By value (this is the default): think of these as being in-only
• By reference as a ref parameter: think of these as being in-and-out
• As an out parameter: think of these as being out-only

In the Person class, add the following method:

    public void PassingParameters(int x, ref int y, out int z) 
    { 
      // out parameters cannot have a default  
      // AND must be initialized inside the method 
      z = 99; 
 
      // increment each parameter 
      x++; 
      y++; 
      z++; 
    } 

In the Main method, add the following statements to declare some int variables and pass them into the method:

 int a = 10; int b = 20; int c = 30; WriteLine($"Before: a = {a}, b = {b}, c = {c}"); p1.PassingParameters(a, ...