C#: From delegates to anonymous methods to lambda expressions to Func delegates

Let's have a look at how the delegate syntax have evolved since the very first version of the .NET Framework and the C# language until today:

1. Basic delegates, .NET 1.0:

delegate int Add(int number1, int number2);

public int AddNumbers(int number1, int number2)
{
	return number1 + number2;
}

[TestMethod]
public void TestAddNumbers()
{
	var add = new Add(AddNumbers);

	Assert.AreEqual(4, add(1, 3));
}

2. Anonymous methods, .NET 2.0:

delegate int Add(int number1, int number2);

[TestMethod]
public void TestAddNumbers()
{
	Add add = delegate(int number1, int number2)
			{
				return number1 + number2;
			};
			
	Assert.AreEqual(4, add(1, 3));
}

3. Lambda expressions, .NET 3.5:

delegate int Add(int number1, int number2);

[TestMethod]
public void TestAddNumbers()
{
	Add add = (number1, number2) => number1 + number2;

	Assert.AreEqual(4, add(1, 3));
}

[TestMethod]
public void TestAddNumbers()
{
	Func add = (number1, number2) => number1 + number2;

	Assert.AreEqual(4, add(1, 3));
}