A concise reference to the C# programming language, expanded and updated, with a look ahead at C# 5.0. C# is an object-oriented programming language that is similar to Java in many respects but more comprehensive and different in most details. This book offers a quick and accessible reference for anyone who wants to know C# in more detail than that provided by a standard textbook. It will be particularly useful for C# learners who are familiar with Java. This second edition has been updated and expanded, reflecting the evolution and extension of the C# programming language. It covers C# versions 3.0 and 4.0 and takes a look ahead at some of the innovations of version 5.0. In particular, it describes asynchronous programming as found in 5.0. Despite the new material, C# Precisely remains compact and easy to navigate. It describes C# in detail but informally and concisely, presenting lambda expressions, extension methods, anonymous object expressions, object initializers, collection initializers, local variable type inference, type dynamic, type parameter covariance and contravariance, and Linq (language integrated query), among other topics, all in aabout 250 pages. The book offers more than 250 examples to illustrate both common use and subtle points. Two-page spreads show general rules on the left and relevant examples on the right, maximizing the amount of information accessible at a glance. The complete, ready-to-run example programs are available at the book's Web site, http://www.itu.dk/people/sestoft/csharpprecisely/