C# – namespace naming conventions


For those of you out there writing reusable components, what do you consider to be best practice if you're extending the functionality of the .NET framework?

For example, I'm creating a Pop3 library at the moment as one doesn't exist in .NET. Do I create a custom namespace or do I use System.Net.Mail ?

Best Solution

From the Namespace Naming Guidelines:

The general rule for naming namespaces is to use the company name followed by the technology name and optionally the feature and design as follows. Copy Code


Generally it's a really bad practice to start including things into the default namespace of a framework or library. This can cause confusion in terms of whether a new namespace is part of the existing library that is part of a framework that is distributed to everyone, or is part of a custom framework that was added by someone else.

Also, the naming convention tries to avoid namespace collisions by having unique identifiers such as CompanyName. It also reduces any confusion and issues in terms of the source of the new library.

This is not only a Microsoft thing, but in the Java as well. Namespaces in Java, called "packages" has the following convention:

The prefix of a unique package name is always written in all-lowercase ASCII letters and should be one of the top-level domain names, currently com, edu, gov, mil, net, org, or one of the English two-letter codes identifying countries as specified in ISO Standard 3166, 1981.

Subsequent components of the package name vary according to an organization's own internal naming conventions. Such conventions might specify that certain directory name components be division, department, project, machine, or login names.

So, if I had a super awesome piece of software, it may be in the net.coobird.superawesomesoftware package.

And using package names that contain the default java., javax., com.sun. packages are a big no-no.