When comparing C# vs Smalltalk, the Slant community recommends Smalltalk for most people. In the question“What is the best programming language to learn first?” Smalltalk is ranked 7th while C# is ranked 14th. The most important reason people chose Smalltalk is:
You can modify the system as it's running. You're "swimming with the fish", instead of probing a black box by remote control.
Ranked in these QuestionsQuestion Ranking
Pro Awesome IDE for Windows
On Windows, Visual Studio is the recommended C# IDE. It provides a very flexible GUI that you can rearrange the way you want and many useful features such as refactorings (rename a variable, extract some code into a method, ...) and code formatting (you can pick exactly how you want the code to be formatted).
Visual Studio also highlights your errors when you compile, making your debug sessions more efficient since you don't have to run the code to see the mistakes. There's also a powerful debugger that allows you to execute the code step-by-step and even change what part of the code will be executed next. In addition to giving you all the line-by-line information you'll need in a hassle-free manner, Visual Studio has stuff you can click on in the errors window that will take you to the documentation for that error, saving you several minutes of web searching.
In addition to all of this, Visual Studio has an intuitive, intelligent, and helpful graphical user interface designer that generates code for you (the best of WYSIWYG, in my opinion), which is helpful for new programmers. Being able to create a fantastic-looking UI with one's mouse and then optionally tweak with code helps make programming fun for beginner developers.
Visual Studio also has the best code completion --Intellisense is every bit as intelligent as the name says it is. It, as well as VS's parameter hinting, is context-, type-, user-, and position-sensitive, and displays relevant completions in a perfectly convenient yet understandable order. This feature allows a new programmer to answer the questions "What does this do?" and "How do I use it?" right then and there rather than having to switch to a browser to read through extensive documentation. This allows the programmer to satisfy their curiosity before it is snuffed out by several minutes of struggling through exhaustive documentation.
And for the more adventurous and text-ready developer, Microsoft does the best job of ensuring that everything, from interfaces and wildcard types down to Console.WriteLine("") and the + operator, is well-documented and easy to understand, with relevant and well-explained usage examples that manage to be bite-size yet complete, simple yet truly helpful. The reference site is easy to navigate, well-organized, clean and uncluttered, up-to-date, and fresh and enjoyable to look at, and every page is well-written with consideration for readers who are not C# experts yet want to read about changing the console background color.
The best part? It's free! Visual C# Express contains all of the features described above, at zero cost. If you are a student, you can probably get Visual Studio Professional from your university, which also includes tools for unit testing and supports plugins.
Pro .NET is a great toolbox
C# runs on top of the .NET framework, which provides many libraries containing classes used for common tasks such as connecting to the Internet, displaying a window or editing files. Unlike many other languages, you don't have to pick between a handful of libraries for every small task you want to do.
Pro Incredibly Well-Engineered Language
Where other languages invoke the feeling of being a product of organic growth over time, C# just feels like an incredibly well-designed language where everything has its purpose and almost nothing is non-essential.
Pro Great introduction to object-oriented programming
Object-oriented programming is the most widely-used paradigm. C# offers support for common OOP features such as classes, methods and fields, plus some features not found in competing languages like properties, events and static classes.
C# code is much more readable thanks to the syntactic sugar it offers. You can truly concentrate on your code, not on the way it's implemented.
Pro Supports some functional features
C# is primarily object-oriented, but it also supports some features typically found in functional languages such as lambdas, delegates and anonymous classes. Methods can be treated like any other object, and the Linq query system operates on monads with lazy evaluation (though it hides this with a lot of syntactic sugar).
You don't need to use these features to code in C#, though, so you can start with OOP and then learn about them.
Pro Best language for Windows programs
C# is clearly the best choice for Windows programs. The .NET framework contains everything you need to build great-looking apps, without having to learn the confusing Win32 API or download a ton of external libraries. C# can also be used to build Windows 8's "modern" apps.
Pro Very high demand in the industry.
C#'s been around for just the right amount of time, is regularly updated with useful additions, is versatile, easy to write & read, & has excellent tooling support. This means it is a top choice for many organisations & will remain so for the foreseeable future.
Pro Can mix high and low level programming
You can code at the high level without worrying about pointers and memory management, but if you so choose you can switch to lower level programming with direct memory management and pointer manipulation (though you need to compile to specifically allow this).
Pro Supported on many platforms
C# can be used for Windows apps, Linux apps, OS X apps, Windows 8 "modern" apps, websites, games, iPhone apps, Android apps, Windows Phone apps, and more.
If you want to create a cross-platform application, you can share most of the code and write one GUI for each platform.
Pro With ASP CORE a good language to learn
With CORE you are no longer just limited to Windows, so a language worth learning.
Pro .NET truly universal
With .NET core it is a truly universal programming language which support desktop apps (Windows), Mobile apps (Xamarin), Web Apps (ASP.Core MVC). Also is perfectly fit to serverless programming for micro services. Soon it will be also support Web assembly (Blazor).
Pro Great language for Unity game engine
Unity provides a selection of programming languages depending on preference or knowledge - C#, JS, Boo and UnityScript. C# is arguably the most powerful with better syntax and stronger language structure. It allows using script files without attaching them to any game object (classes, methods inside unattached scripts that can be used at any time). There are more tutorials and information for C# than UnityScript and Visual Studio can be used to code for unity in C#. Additionally, learning C# allows using it outside of Unity as well unlike UnityScript.
Pro Awesome IDE for cross-platform development
Visual studio has embraced cross platform development over the past 3 years. With Visual Studio Code, you now have a light, and quick IDE variant available for free as well.
Pro Environment of live objects
You can modify the system as it's running. You're "swimming with the fish", instead of probing a black box by remote control.
Pro Easy to learn and experiment
Pro Elegant syntax fits on a postcard
The syntax was designed to be easy enough for children to learn. Beginners can learn the language rules very quickly and then focus on programming without fighting the syntax at the same time. Things that have to be baked into the grammar in other languages are simple message sends with block arguments in Smalltalk. Expressions have only three precedence levels to worry about.
Pro Pure and easy object orientation
Smalltalk is one of few languages that are purely object oriented. This provides a solid and easy to understand base on which to learn object oriented programming, the most popular approach to programming.
Pro Superb Integrated Development Environment (IDE)
All tools (Inspector, Browser, Debugger etc.) are written in Smalltalk and are live objects in the environment. All sources are present, so that the tools can easily be studied, changed and experimented with.
The same goes for the other components like the compiler, OS-Integration etc.
Pro Agile "interactive" test-driven development
Smalltalk had the original (and still the best) unit test system that inspired it in many other languages (like Java's JUnit). Working with interactive live objects in Smalltalk style TDD makes it easy to teach and learn TDD.
Pro Powerful integrated debugger
You can edit code and swap it in while the program is still running after an exception has already been signaled, or restart from anywhere in the call stack. You can inspect and modify the state of any object. Some Smalltalkers write unit tests and then program exclusively in the debugger.
Pro Inspector makes objects transparent
Programmers must make detailed mental models of the system they are developing. Bugs usually happen when the mental model does not match the actual system. This is one of the greatest difficulties beginners have because most systems are so opaque. It takes a lot of effort to see what's really going on. But in Smalltalk this is much easier, thanks to the powerful tools included in the environment, like the object inspector.
Pro Internal source code and documentation
You can explore how everything works easily.
Pro Incremental compilation
Smalltalk provides an extremely fast code-compile-run-debug cycle. You don't have to stop and reset the world to tweak your program, since you can compile one method at a time while the environment is still running. This is great for beginners to experiment and prototype ideas.
Pro Inspired many other languages' object systems
Pro Open source
MIT licensed implementations Pharo, Squeak, Cuis & Dolphin
and GPL licensed GnuSmalltalk.
Pro Save and restore virtual machine image
A Smalltalk environment can save the state of a running program and later restore and resume execution. This includes the internal state of live objects, multiple thread stacks, and debugging sessions, making it easier for beginners to take the exact problem to an expert for assistance.
Pro Language uniformity
This leads to a very simple programming model (pure OO) that is still very powerful. A lot of stuff that is hard to implement in other languages is easier in Smalltalk.
Pro Graphical user interface
Beginners are usually stuck making command-line applications in other languages, because GUIs are too hard. Smalltalk GUIs are easy enough to start with.
Pro First-class functions with lexical closures
Also known as "blocks". These objects contain reusable snippets of code and as first-class objects they can be passed as arguments to other methods or blocks and also returned from them. "lexical closures" mean they retain access to the variables in the lexical environment they were written in, that is, in the surrounding code.
Pro It invented a lot of stuff
Smalltalk is the inventor of Just-in-Time compilation and the MVC concept, refactoring through their so-called refactoring browser and it was also one of the first adopters of a language virtual machine, closures, live programming, test driven development, an IDE and the development of GUI`s.
Pro As a first language, almost forces you to learn OO design
Hybrid languages (e.g., Java, C#, C++) make it easy to slip into procedural thinking. Smalltalk's pure OO approach makes it hard not to think in object-oriented terms. In addition, since the entire IDE and runtime components are there in the image for you to browse, you have plenty of examples of good OO design to learn from.
Pro Provides a functional way to interact with objects
Many languages today use object orientation, while the most of them stock on the half way in that perspective.
Smalltalk sees literally everything as an object and this includes things like the classes and primitive data types. There is are zero control structures such as selection and iteration, since all is done by sending messages to objects.
It use a lot of concepts from Lisp in order to provide a nice experience for this pure kind of object orientation.
It provides immutable data structures, closures, anonymous functions and higher order functions, while all those functions are objects. This is what makes Smalltalk so simple, elegant, and easy.
All this counts for Pharo, while other implementations as Amber are probably feature complete to it.
Con Dependecy on IDE
Most people learn and depend on VisualStudio to write C#. The result is people learn how to use an IDE and not the concepts or fundamentals of good programming. This isn't necessarily a knock on the language itself, but it is frustratingly difficult to do things in C# when not using VS.
Con Too easy to write multithreading apps that are buggy
Many web frameworks or GUI libraries will push novice users to writing multithreaded code, which leads to frustrating race condition bugs.
Other languages with multithreading push users towards safe constructs, like passing messages and immutable or synchronized containers. But in C# the data structures aren't synchronized by default, and it's too easy to just set a field and observe the result from another thread (until you compile with Release, and now you have a heisenbug).
Con Often-used products in most C# development environments get expensive
The majority of the C# development community uses Microsoft products which are not all free and open-source. As you get into the enterprise level of some of these products and subscriptions, the expense is multiple factors of 10 greater.
While you can use a fully open-source and free C# environment, the community around that is much smaller. While this can be said for other languages as well, the majority of C# falls into the for-pay Microsoft realm.
Con Complex syntax
Too many syntactic constructs to learn before it becomes usable.
Con Lacks standard-library support for immutable data structures
Con OO is becoming obsolete
Smalltalk did it best, but the whole paradigm is a poor fit for the expected future multicore processors. Isolated mutable variables with no compile checks is a recipe for race conditions in multithreaded code. Beginners would be better off learning a functional language.
Con Not common
Smalltalk missed an opportunity to become mainstream when its implementations cost $5000 per seat versus $0 open source. New open source implementations (Pharo, Squeak) have minor corporate backers but not yet an IT behemoth. Direct jobs are scarce (but indirectly Smalltalk experience is very well regarded). Online communities are relatively small.
Con Not useful for mobile development
While Smalltalk is very powerful and easy to learn, it doesn't have a well supported mobile distribution, but you'll be spoiled for working in mainstream languages like Java, Swift or Kotlin where jobs are more readily available.
Con Virtual machine in its own isolated world
Smalltalk wants to be the whole OS. While this has tremendous advantages internally, interacting with the world outside the VM is not as easy as pure Smalltalk and must be done via a Foreign Function Interface.
Con Non-standard arithmetic ordering
Since every operation is considered a message sent sent is a specific order, all arithmetic operators have the same precedence. E.g. 2 + 3 x 4 translates to 2 + 3, and the result is multiplied by 4, giving an answer of 24 (instead of the correct answer - 14). Once you are learn this, it can easily handled using brackets, e.g. 2 + (3 x 4), but still a momentary suprise for beginners.