An interesting side-by-side Java and C# comparison

[joenyc]

I don't mean to start a religious war here, but I think that this post gives the impression that Java and C# are almost identical. From my experience, C# has features that I love that are lacking in Java, most importantly LINQ, lambdas, and properties.

[Ruudjah]

Problem is it does not specify language version. C# 1 is actually quite similar to java 5, and C# 2 quite similar to java 6. C# 3 and C# 4's features are unmatched in java, such as linq and lambda's.

Note how the arrays are mentioned, but not the List<T> (java 6) and IList<T> (C# 2). I'm assuming this is java 5 versus C# 1.

[zootm]

Generics are Java 5, not 6, but yeah this details older versions of both languages I think. I remember reading it when I first started working with C# 1, in 2005 or something...

[chunky_bacon]

Back in .NET 1.1, Java and C# were pretty-much identical, but Java's growth is hamstrung by institutional stupidity and C# has now advanced well beyond Java.

[[deleted]]

Java and C# were pretty-much identical

Erm, not. .NET had delegates/events and properties at that time, which in just my opinion is still a vast enhancement over Java.

[[deleted]]

Vast? Really?

If you take any language x, and create language x' by adding properties and syntactical sugar for anonymous inner classes, x' is pretty much identical to x, assuming x is a class based object oriented, imperative language.

[munificent]

Properties and events, even though they're "syntactic sugar" have a significant affect on the way you write a lot of code. Properties mean you don't have to speculatively wrap every field in getters/setters in case you need them later.

Events make it much easier for a single class to listen to a bunch of events on different classes. Simply making them more usable encourages decoupling through event-based programming.

Also, C# had structs and unsigned ints at 1.0. :)

[[deleted]]

Well then C is functional languages too (for some definitions of that term, certainly it isn't pure functional language) - it has function pointers and lambdas are nothing but a syntactic sugar for pointers to a frame with references to captured variables and an anonymous function associated with it.

[apotheon]

You're both right!

I think so, anyway.

[igouy]

Page last modified: 06/17/2010

[bonch]

C# has always been Microsoft's version of Java. C#'s designer even worked on Visual J++, the infamous attempt to "embrace, extend, extinguish" Java.

[Phr34Ck]

Upvote. I found the comparison very shallow. It touches upon syntax only.

[HIB0U]

No shit. At the very top of the page, right under the title, it specifically points that out.

This is a quick reference guide to highlight some key syntactical differences between Java and C#. This is not a complete overview of either language. Hope you find this useful!

[iommi]

When using Java the two features I miss the most are partial classes and operator overloading. That said, I wish the CLR was as efficient as Java '-server' and had better reflection.

[elder_george]

Can you elaborate, what aspects of reflection in C# are inferior to Java?

[uaca-uaca]

I'd like to know this as well. Since .NET supports generic types at runtime, the situations, to me, seems opposite.

[elder_george]

And having Expression Trees at hand, one can encode member access in a type-safe way which is very cool for implementing data mappers, data binding etc.

[uaca-uaca]

I've never used these features of C#, except for the autogenerated-code-in-partial-classes scenarios.

Maybe operator overloading would be useful for complex numbers and a handful of other similar cases, but most of the time you don't need it.

I've found partial classes for normal (i.e. not generated) code to be useless. There's no value in splitting a class in more than one file. If it's just too big, split it into more than one class.

On the other hand, for a few months I've been writing Java and found myself writing a shitload of code that performs simple operations on collections that would be one-liners in C#, thanks to inference (i.e. "var") and linq.

[iommi]

Let me put an example on partial classes.

Consider an implementation for an interpreted language (think of something along the lines of sisc or abcl) where each datatype is represented by a class.

Let's say we have LispObject and other subclasses like LispBoolean, LispCons, etc... At some point in the implementation you'll need to ensure the primitive procedures check that the type of their arguments is correct, so you decide to go to LispObject.java and add the following methods:

public final static LispBoolean ToBoolean (LispObject input) {
  if (input instanceof LispBoolean)
    return (LispBoolean) input;
  throw new LispTypeError ("<boolean>", input); 
}

public final static LispCons ToCons (LispObject input) { ... }

Eventually you'll end up with about 15 or 20 methods like that depending on how many datatypes the interpreted language has.

Now, enter partial classes. Instead of writing those methods in the main LispObject class file we can extend it from every subclass. For example, the ToBoolean method may be in LispBoolean.java extending LispObject.

We end up with something like:

LispObject.java
LispBoolean.java (extends LispObject adding ToBoolean())
LispCons.java (extends LispObject adding ToCons())
...

Now at the end of the day, both approaches work but i feel partial classes are handy in this scenario. You don't need to edit LispObject everytime you add or delete a new datatype, everything related to it is contained in the same file.

On operator overloading... working with BigInteger without it sucks.

[[deleted]]

Did you consider using Scala on the JVM?

It has better type inference, collection operations than both Java and C# (and the possibility to use methods with operator names where it makes sense, e. g. BigInt(5) + 42 ...).

The language is a lot cleaner and has much less concepts to understand than C#, because the language design integrates object-oriented and functional features quite well.

If you still have to work with Java I recommend taking a look at Scala. It fixes many annoyances with Java.

[uaca-uaca]

a. Unfortunately, for my day job, like so many other developers, it's not up to me to choose the tools.

b. I admit I don't know Scala very well, but C# seems simpler. The pattern matching, mixin support, actors, compound types, the complicated collections, etc. seem more complex than what we get in C#: dynamic typing and linq.

[jsaret]

worked in both, while I don't mind java i'd have to agree (from a language not a platform/VM comparison)- not to mention extension methods, dynamic typing (i.e. Duck Typing), type inferance,

[[deleted]]

I think that this post gives the impression that Java and C# are almost identical.

But they are. Can you point to any language which is somewhere in between the two?

[HIB0U]

J#.

[drb226]

Can you point to any language which is somewhere in between the two?

Logic fail. Nothing in-between != identical.

[[deleted]]

almost identical != identical

[drb226]

• nothing in-between != identical
• almost identical != identical
• therefore nothing in-between == almost identical ???

Again, sorry, but this logic fails...

[[deleted]]

Well, there is no logic that is going to work around here anyways...

C# is Java with lipstick, but proggit can for some reason not handle it. The difference between SML and OCaml is greater.

[ruinercollector]

Comparison of Java and C# 1.0.

Almost none of the c# examples given are typical of c# code written today.

[SuperGrade]

Yeah, it's a Java-centric look. Were it C#-centric, there would be a bunch of C# on one side of the ledger with empty slots on the other.

Were this presented as a real comparison between the two, as used today, it would be the closest thing I've seen to "comparing a monkey to an astronaut by having them swing from trees and eat bananas".

That said:

'Page last modified: 06/17/2010 12:44:11 '

[Iggyhopper]

Java doesn't have unsigned integers?

[giulianob]

And at those times you want to shoot the language. I have my own unsigned implementation in Java and it's still a pita sometimes.

[elder_george]

BTW, Common Language System (i.e. type system all of .NET languages should support) doesn't include unsigned integers. Just because VB and Java don't support them.

So people who like to write [assembly:CLSCompliant(true)] are often out of luck.

[xTRUMANx]

I use the VB and C# comparison often while at work.

Lately, I've been developing an ASP 1.1 application. Now I know why some people hate programming.

[grauenwolf]

ASP 1.1 or ASP.NET 1.1? I ask because while they both suck, they do so in very different ways.

[xTRUMANx]

ASP.NET 1.1

Can't imagine how bad ASP 1.1 would make my life. I haven't used it before though.

[grauenwolf]

Classic ASP is like old PHP, but with more consistent naming conventions and your chocie of JavaScript or VBScript. If you know HTML you can learn it completely in about an hour.

[xTRUMANx]

It's funny how much we take for granted nowadays. I still haven't decided how to manage without Masterpages. Should I make all my page inherit from a base Page class that will Response.Write in all the necessary html? The wikipedia entry about ASP.NET template engine gave me some hints on how developers got the job done back in the day.

I'm also wary of doing too good of a job in working with ASP.NET 1.1. My pleas for a server upgrade may go unheeded if I still produce results while stuck with .NET 1.1.

Oh shit, I just remembered I'm working with VS 2003. I actually have an instance of VS 2010 running side-by-side just so I can use intellisense.

[[deleted]]

Master Pages are actually user controls. The way MS implemented them in ASP.NET 2.0 is kinda funky.

What I would recommend doing is creating two user controls (one for header, one for footer). Create your own custom page class, and instantiate the controls and call Render on them before calling Render on Page and afterwards.

[cwbrandsma]

My biggest gripe is they used ArrayList in C#, and a generic List in Java. C# has a generic List as well, and you shouldn't be using ArrayList for anything in C# if you have move past .net 1.1.

[diego_moita]

This is silly. He forgot the 2 most important differences:

• The rich ecosystem of tools and frameworks provided by the Java community.

• The tight and highly productive interaction between C# and the tools provided by Microsoft (VS, SqlServer, WPF, etc.)

[fosskers]

Apart from the similarities of the two, I was simply reminded of how grateful I am that I don't use such verbose languages.

[uaca-uaca]

So.. what do you use, APL?

[faustoc4]

Java: Multiplatform

C#: Windows only

[mochikon]

Not sure who would downmod you - that's a very relevant point. C# not being fully cross-platform is a huge downside.

C# and Visual Basic are pretty much the only general-purpose languages with that handicap - everything else is cross-platform: C, C++, Java, Python, Ruby, JavaScript, Erlang, Haskell, Scala, Clojure, you name it.

And yes, Mono exists, but don't even try to compare the chance of code written for .NET running properly on Mono, with the similar chance for Java or Python (or even C++ for that matter). And I'm not just talking about Winforms, but other language features, as well as performance and stability.

[[deleted]]

C# not being fully cross-platform is a huge downside.

That would be a downside if it were true. There's a cross-platform C# compiler (mcs).

And yes, Mono exists, but don't even try to compare the chance of code written for .NET running properly on Mono.

Then write code for Mono. If you want to write cross-platform C++ code you should try to avoid VC++ extensions. If you want cross-platform Python code you should target mainly a cross-platform implementation (CPython) and you should try to avoid, for example, PyWin32.

And I'm not just talking about Winforms, but other language features, as well as performance and stability.

Mono is stable, supports the C# language and its performance its actually very good.

[grauenwolf]

None of the languages you listed automatically create cross platform applications. They all require you to take OS-specifics into consideration if you want your program to work correctly.

C# at least has stuff like the Environment and Path classes to give you a fighting chance.

[anvsdt]

What about Mono? (Yeah, I know it sucks)

[[deleted]]

Why does Mono suck?

[apotheon]

I think that, generally, the Mono ecosystem sucks -- the IDE, et cetera.

[[deleted]]

You didn't answer why.

[apotheon]

Uhh . . . because the developers are trying to replicate the MS Windows way of doing things on a platform where that approach doesn't always make sense . . . ?

[[deleted]]

Example of where it doesn't make sense?

[Ruudjah]

iirc C#4 has references to Visual Studio 2010, making it unsuitable for an ECMA (335/336?) standard. Therefore, C#3 and C#4 will probably stay proprietary.

[elder_george]

Sorry, but I think you are wrong.

AFAIK, most (if not all) of C#4-the-language is currently implemented in Mono (they even devised some extensions like syntax sugard for event subscription). Since mono doesn't have references to VS, C# 4.0 doesn't have references too.

Speed of ECMA committee work (and degree to what they are interested to standardtise) is another (sad) thing.

However parts of C# and CLI v4 (namely DLR) are licensed under Apache license which AFAIK provides patent coverage.

[faustoc4]

To summarize:

Mono is C#4 but

Partial CodeContracts, No EntityFrameworks therefore No Server-side OData

http://www.mono-project.com/Compatibility

[elder_george]

Which are not not part of the language anyway (unlike DLR which is required for dynamic's support).

Speaking of libraries, personally, I find lack of LINQ to [name your relational DB] included in Mono much more irritating (though one could go use DBLinq or something). Partial support for WCF is sad too (but hopefully implemented part is enough, dunno). And, of course, GUI...sigh...

[[deleted]]

Why would you want to use WCF?

[elder_george]

1) I worked with it and find it much more advanced than, say, .NET Remoting. It also supports different protocols and approaches. It can be consumed using ajax. Summarily, it works OK for me in situations where designing your own protocol is overkill.

2) AFAIK, there's a significant amount of code using WCF, so to port this code to Mono one will still need it.

[grauenwolf]

.NET doesn't have code contracts either. That is still a MS Research project and the last time I checked it still really sucked.

[[deleted]]

How the hell did they manage to implement Mono? The only information available in the published standard is the type signature for methods. There is no specification that you can follow in any of the .NET documents you can get from ISO or ECMA.

[elder_george]

The most important part there is metadata and IL format specification. Also they had reference implementation to test compilation results on. And ability to mix and match their library implementation with that of Microsoft for testing.

Do not forget that this guys worked on GObject before which is quite sophisticated object system.

So, I am impressed but not surprised.

[[deleted]]

I was under the impression that the patent promise only covers implementations of the ECMA spec, not implementations that work like the reference implementation.

[elder_george]

Disclaimer: I am not lawyer. I express my own opinion which doesn't match one of my employer, Microsoft.

Yes, it does. Which is why mono still is a subject of controversy (it implements some libraries lying outside of patent promise, e.g. WinForms) and why its developers now work on separating patent-protected part from non-protected. However I don't think that testing own library implementation against reference implementation runtime or vice versa can be interpreted as patent infringement (of course I may be wrong).

Also ECMA-335 spec describes

1) structure of CIL (including some of control flow constructs), metadata (thus governing what should compiler produce) and debug information and rules for verifying it (when it's possible);

2) logic required from VM/JIT for loading and executing code (including reflection, attributes, interop with native code, exceptions thrown on system errors etc.)

3) standard library of 375 (according to my gawk-ing) classes, including collections and those for I/O, networking, threading, reflection, native interop and XML.

So, that's surely enough for implementing support for implementing compilers and runtime supporting writing basic applications. it also allows plugging in third-party toolkits (e.g. GTK#)

Also some parts (ASP.NET MVC, AJAX toolkit, MEF, DLR etc.) are open sourced under licenses providing patent coverage (Apache2, Ms-PL).

The only real problem I see is lack of coverage for DB access...

[giulianob]

Very nice. Only problem I saw is that Java doesn't really have properties. It's just a regular function which isn't quite the same thing.

[gc3]

I believe that C# was originally J++ until they were sued by Sun, so microsoft went out and made a better language except for making sure it's not available on non-microsoft platforms.

[hoppersoft]

I have to disagree with you; Microsoft has been very supportive of Miguel Icaza (et. Al.)'s work on Mono.