The .NET Framework Class Libraries

As an example, let's first take a look at the standard "Hello, World" application in C++ and then compare it to an application that does the same thing in C#: -

#include <iostream.h>
int main(int argc, char* argv[])
{
    cout << "Hello, World!" << endl;
    return 0;
}

Notice that the application first includes a header file with the declaration of the cout function. The application's main function-every C/C++ application's entry point-uses the cout function to write the string "Hello, World" to the standard output device. However, what's important to note here is that you can't write this application in any .NET language without the .NET Framework class libraries. That's right: .NET languages don't even have the most basic compiler features, such as the ability to output a string to the console. Now I know that technically the cout function is implemented in the C/C++ runtime, which is itself a library. However, basic C++ tasks such as string formatting, file I/O, and screen I/O are at least logically considered part of the base language. With C#-or any .NET language for that matter-the language itself has almost no ability to do even the most menial task without the .NET Framework class library.

Let's look at the "Hello, World" example in C# to see what I mean: -

using System;
class Hello
{
    public static void Main()
    {
        Console.WriteLine("Hello, World");
    }
}

So, what does this common set of class libraries mean to you, and is it a good thing? Well, it depends on your vantage point. A common set of class libraries means that all languages, theoretically, have the same capabilities because they all have to use these class libraries to accomplish anything except declaring variables.

One gripe I've seen on discussion boards is, "Why have multiple languages if they all have the same capabilities?" For the life of me, I don't understand this complaint. As someone that has worked in many multilanguage environments, I can attest that there's a great benefit to not having to remember what language can do what with the system and how it does it. After all, our job as developers is to produce code, not to worry about whether a favorite language has this advantage or that advantage.

Another question I've seen frequently is, "If all these .NET languages can do the same thing, why do we need more than one?" The answer relates to the fact that programmers are creatures of habit. Microsoft certainly didn't want to pick one language out of the many available and force millions of programmers to toss out their years of experience in other languages. Not only might a programmer have to become familiar with a new API, he or she might have to master a completely different syntax. Instead, a developer can continue using the language that's best suited for the job. After all, the name of the game is productivity. Changing what doesn't need to be changed is not part of that equation.