C# for Java Developers

joefrench writes: "It might seem strange to review a C# book on Slashdot, especially one published by Microsoft, but I felt that there must be a lot of readers like me -- programmers who know Java, but want/need to learn something about C# and .NET. C# for Java Developers aims to teach experienced Java programmers how to write in C#." Joe outlines what he considers the book's good points (many) and weak points (few) in the rest of his review, below. C# for Java Developers author Allen Jones, Adam Freeman pages 548 publisher Microsoft Press rating 9 reviewer Joe French ISBN 0735617791 summary A comprehensive C# from Java tutorial

First things first First of all, let's deal with the Microsoft issue. I was surprised to find that this book even existed given the problems MS has had in the courts recently. I was even more surprised to find that C# for Java Developers is very balanced and does not hype up C# at the expense of Java -- throughout the book there are places where the authors say that "Java is better at this" or "We have no idea what the C# designers were thinking." A refreshing attitude from a company that is not known to be an admirer of Java.

I was reluctant to pay for a Microsoft book, but I have to admit that I am impressed. This is the first MS book I have ever purchased, and it is clearly written, well thought-out and very, very comprehensive. One of the best features for me is that all of the instructions for compiling and managing code assume that you are using the command-line tools, rather than Visual Studio. For someone on a tight budget, this was a real bonus.

The Scoop

The first part of the book is an overview of .NET, and contains the boiler-plate description that you get from the .NET web site. Not that useful, but pretty short. There is a chapter that compares .NET to Java (J2SE and J2EE), but again, there is nothing new or important there.

The second part of the book covers the C# language, using Java as a starting point. The coverage seems comprehensive, and explains where the two languages are the same (quite often), where they are different (now and then) and when they appear to be the same, but you are likely to spend a couple of hours tracking down something weird (more often than I would like). I had started playing around with C# before buying this book, and all of the problems that I had in the early days were detailed here with clear explanations.

Part three delves into the .NET class library, covering basic topics such as collections, IO and handling XML. Once again, I was impressed with the depth of coverage and the way in which the authors use Java classes to explain the workings of .NET. It was while I was reading through this section that I realized just how different C#/.NET and Java can be.

The last part of the book covers "advanced" topics. There seems to be little reason for the division between basic and advanced topics, but chapters cover areas such as threading, security and networking. The one thing that is consistent in this part of the book is that there is less of a parallel between Java and C#. For example, "Windows Forms" is used to build client UI applications, but is very different toolkit from Swing/AWT.

The appendix list is a little dull, covering topics like GC and configuration files. There are some interesting snippets, but I got the impression that these were topics that the authors thought were important, but didn't know where else they should go. The exception is the "Java to .NET API Reference" which, for me at least, sets this book apart from the competition. Every class from the J2SE class library is mapped to an equivalent .NET class and a reference to where the topic is covered in the book -- having something like this has saved me hours of searching.

What's to Consider?

This book uses a lot of C# fragments to demonstrate how classes are used, but contains very few full "working" examples. I found this to be great once I knew the basics of C# (because I could focus on the topic), but difficult at first (because I could not play with complete code).

C# for Java Developers covers much more of the .NET Framework than the other books in my local bookstore, but because of this the text can be dense at times, as the authors try and pack in a bit too much detail.

I can't find major fault with this book, and a (small) part of me admires Microsoft for publishing such an unbiased book.

Summary

If you are a Java programmer who wants or needs to learn about C# and .NET, then this is a great book. Don't be put off by the Microsoft logo, and bear in mind that you don't need a copy of Visual Studio to follow the examples.

The book effectively uses Java as a tool to teach C# and explain the workings of .NET. If you are like me, then you will find this book invaluable and will likely keep it close at hand for quick reference.

Table of Contents

1. Introducing .NET
2. 1. Introduction to Microsoft .NET
   2. Comparing Java and .NET Technologies
3. The C# Language
4. 1. Creating Assemblies
   2. Language and Syntax Features
   3. Data Types
   4. Advanced Language Features
5. Programming .NET with C#
6. 1. Strings and Regular Expressions
   2. Numbers and Dates
   3. Collections
   4. Streams, Files, and I/O
   5. XML Processing
7. Advanced Topics
8. 1. Reflection
   2. Threading and Synchronization
   3. Networking
   4. Remoting
   5. Database Connectivity
   6. Security and Cryptography
   7. Graphics and UI
   8. Introduction to XML Web Services
9. Appendices
10. 1. Platform Integration
    2. Shared Assemblies
    3. Configuring Applications
    4. Garbage Collection
    5. Cross-Language Code Interoperability
    6. Java to .NET API Reference

You can purchase C# for Java Developers from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Comments

Terrarium

[killthiskid]

The thing that finally got me to play with C# was Terrarium. Players create 'creatures' which then compete in a peer-to-peer set of virtual terrariums. You can create plants, herbivores, or carnivores. It was quite fun (in a super geek way) and VERY challenging.

Refreshing indeed

[Anonymous Coward]

"... very balanced and does not hype up C# at the expense of Java -- throughout the book there are places where the authors say that "Java is better at this" or "We have no idea what the C# designers were thinking."

Try finding that balance in a Java book, most of which devote all of Chapter 1 to a buzzword parade and list of Java perks (prevents bugs, write once run anywhere, cures baldness, etc).

Java developers should use J#, no?

[Anonymous Coward]

J# for .NET is there (its installable already) for Java developers to leverage their Java knowledge in order to create managed applications for deploying on the .NET framework.

Use that.

Re:Java developers should use J#, no?

[Jugalator]

Yep, that's also the #1 reason to use it according to MS.

However, syntax is often the easiest thing to relearn when switching language. Often much easier than to relearn an entire API. And since J# use the .NET Framework (and only the .NET Framework - it doesn't even run a VM) you could just as well go for C#. It's not *that* hard of a transition to relearn at all. For me, it was enough with some tutorial browsing on the internet to get into C# with a couple of years of Java experience since earlier.

Re:C# may not stand for long...

[Anonymous Coward]

Problem is is that VB.NET isn't easier to use. It's actually harder and in many ways fits strangely around the .NET framework. That along with an obvious lean toward C# in all the docs I'd say VB is not long for this world. Look for C# to take over completely in the next 2-3 releases of M$ dev products.

Good starting point online

[km790816]

A Comparative Overview of C#

This is a great site. If anyone wants to learn C# coming from a C/C++ or Java background I send them here. Shows source in all three languages (where applicable). Good place to start.

I must say I was a hard-core Java fan until I found C#. I must qualify that statement since I develop exclusively for Windows.

If you write code that will only live in the Windows world, you owe it to yourself to check out C#/.NET.

Re:Good starting point online

[Kynde]

Your visceral hatred of Microsoft has you defending Java's disgustingly verbose syntactic conventions for properties where yep, they got that wonderful beans model, then proceeded to do absolutely NOTHING with the language syntax to support it.

Couldn't agree more, but the same won't hold for C/C++ which they referred to.

I bet you thought those were direct property accesses, right? I wouldn't expect such a staunch defender of The One True Faith to actually look up the mechanisms of property declarations...

Doh, it being methodized was obvious enough. It just kinda bugged the hell out of me seing :
foo.setSize (getSize () + 1);
label.getFont().setBold (true);


Labeled as "typical code" in C++.

And the part which you were obviously referring to as it cannot be done in C++ (because one can't overload .):

label.font.bold = true

Well, I for one am quite doubtfull wether that is better than what C++ has now :
label.font().bold = true

The article goes on and argues that the .font. syntax won't be mistaken for a field by "However, almost all classes with any real complexity designed in Java (and certainly in C#) do not have public fields anyway.".

Well, I sure don't see the "extra" parentheses harmfull, moreover I'm worried about the complexities of the scoping rules for similarily named fields.

Having read the cursive (italic) parts of the article, I have to say that I don't agree with most of it. And just as my comments here are biased, so is the article. Rants like these don't make good articles. That's why I post my crap here, which would've been a fair idea for that author aswell.

Re:Good Stuff!

[thedarkstorm]

There is a somewhat free version available for Linux. It's called Project Mono I believe. Here is the URL:
http://www.ximian.com/devzone/projects/mono. html

Small SUmmary from page, "The Mono Project is a community initiative to develop an open source, Linux-based version of the Microsoft.NET development platform. Incorporating key .NET compliant components, including a C# compiler, a Common Language Runtime just-in-time compiler, and a full suite of class libraries, the Mono Project will enable developers to create .NET applications and run them on Windows or any Mono-supported platform, including Linux and Unix. Besides greatly improving the efficiency of development in the open source world, the Mono Project will allow the creation of operating-system-independent programs. "

Maligned?

[p00ya]

It's disappointing to see so many developers give c# a rough time. I really do not see how c# is any more maligned than other languages.

It really is just scared developers concerned that anything redmond can cough up is too mainstream and below them...

Take a look at the ecma standards, download mono, and crawl out of your shell.

Re:Maligned?

[Anonymous Coward]

I've been playing around with mono for a while now and think c# is a great language.

It's more complex than java, but also more powerful
with managed code. I love delegates, indexers, and properties. Sure, that's all syntactic sugar, but isn't every language up from assembly?

The one thing I would really like is Eclipse support with code completion and nice docs that can be brought up with F1 or whatever For c/c++ stuff I just use vim and just tag all of the system headers, but with lanagues like java and c#
with huge class libraries, code completion and doc help is pretty nice and makes learning a new language fun.

Re:Maligned?

[Wavicle]

It really is just scared developers concerned that anything redmond can cough up is too mainstream and below them...

I'm pretty sure most of us developers are just a frightful bunch. Ada is an infamously derided language ("oh the government made it, so it's basically a beauracracy of a language") - yet it has more built in support for requirements validation and maintainability. If you look carefully at Ada, it is a pain to work with, but the result can be readily and meticulously examined by people other than the original developers.

If you were a sailor and an exocet was screaming towards your vessel 500 yards out and skimming the waves and the only thing between walking the deck and treading the waves is your Phalanx close-in weapon system, you're probably hoping the software which controls the Phalanx was developed with Ada. Now would not be the time to file a support request because your C++ caused a general protection fault.

So whether it's C# or anything else... I think way too many are afraid of having to re-stock their toolset from scratch. There's comfort in working with what you've always worked with. Insert cliche dinosaur analogy here.

Re:C# may not stand for long...

[Graspee_Leemoor]

" can any single one of you actually describe, in under 200 words, exactly what the .NET Framework is, what its comprised of, and why I should find it so exciting? "

The .net framework is a collection of command-line compilers for various languages which produce bytecode. It also includes the compiler from bytecode to native-code, a disassembler and the .net classes. Basically the .net framework is everything you need to compile and run .net code. It is free as in beer.

There you go. Pipe that to wc -w and I think you'll find I win.

graspee

Re:Wow- C# review on Slashdot?

[glh]

No, C# doesn't allow you to write unsafe code, you have to use C++ for that. What's new about C++ in the .NET framework is that it allows you to mix safe ("managed") code with unsafe code. In managed mode, it's a rather castrated C++ (particularly the lack of templates), but with the niceties of GC.


You can write UNSAFE CODE with C#. Yes, it is mixed in, but it is still unsafe code. See this article for reference.

I never said it runs outside the CLR, just the GC.

Re:Good Stuff!

[pmz]

Hey! If that's true, can't sun sue them for use of a trademarked acronym?

Not quite, since Java is widely implemented. Sun doesn't expend time and money trying to make these implementations incompatible; instead, Sun wants them to be compatible and has test suites available for that purpose. Conversely, Microsoft has a history of prefering their implementation over any others and works hard to drive other implementations into obscurity. Only time will tell if history will repeat itself with respect to efforts such as Mono.

...do you REALLY expect to get EVERYTHING for free?

No, but I do consider the amount of risk associated with a technology. .NET provides a one-way ticket to the Microsoft Village; if you are comfortable with that, then, by all means, use C# and be happy. Those people looking for multiple-vendor technologies (i.e., lower risk technologies) should look elsewhere.

Re:C# may not stand for long...

[JamesOfTheDesert]

And since it only runs on Windows, hence x86, I need to produce bytecode why?

So you can run it on FreeDSD or Linux using Rotor or Mono.

EvanED has it wrong I think.

[sweetjonnie]

Dear EvanED,

For someone who has done a good deal of research on languages, I find it odd that you should point to four of THE most superficial differences.

Had you pointed to differences between the CLR and the JVM, you might have had an audience.

Instead, you rehashed the oulde argument between C++ and Java. Who won that debate? The people who realized that it was a waste of time to argue THESE points.

EvanED, I wish you well in your research. I would like to point out to you that there is not a junior college on Earth that will give you any extra credit for your penetrating analysis.

Sincerely,
sweet jonnie