C# 3.0 Pocket Reference, 2nd Edition

Anonymous Types (C# 3.0)

An anonymous type is a simple class created on the fly to store a set of values. To create an anonymous type, use the new keyword followed by an object initializer, specifying the properties and values the type will contain. For example:

	var dude = new { Name = "Bob", Age = 1 };

The compiler resolves this by writing a private nested type with read-only properties for Name (type string) and Age (type int). You must use the var keyword to reference an anonymous type, because the type’s name is compiler-generated.

The property name of an anonymous type can be inferred from an expression that is itself an identifier. For example:

	int Age = 1;
	var dude = new { Name = "Bob", Age };

is equivalent to:

	var dude = new { Name = "Bob", Age = Age };

Anonymous types are used primarily when writing LINQ queries.