Quotes from Matt Zandstra

Methods like this act as "factories" in that they take raw materials (such as row data, for example, or configuration information) and use them to produce objects. The term factory is applied to code designed to generate object instances.

Some properties should not be changed. The Answer to Life, the Universe, and Everything is 42, and you want it to stay that way. Error and status flags will often be hard-coded into your classes. Although they should be publicly and statically available, client code should not be able to change them.

The Pragmatic Programmer: From Journeyman to Master by Andrew Hunt and David Thomas (Addison-Wesley Professional, 1999).

Design Patterns: Elements of Reusable Object-Oriented Software (Addison-Wesley Professional, 1995) by