example of ref keyword in C#

refExample.cs

// LinqPad example of ref keyword in C#
// "in c# objects are always passed by reference" -- NOT TRUE!!!
// what actually happens is that references are always passed by value!
// using the ref keyword passes the reference explicitly

void Main()
{
	var s = new StringBuilder("hello");
	Console.WriteLine(s.ToString());
	
	SetNull(s);
	Console.WriteLine(s == null);
	
	SetNull(ref s);
	Console.WriteLine(s == null);
	
}

public static void SetNull(StringBuilder x)
{
	x = null; //<-- this is a copy of the reference to s
}

public static void SetNull(ref StringBuilder x)
{
	x = null; //<-- this IS the reference to s
}