We believe that introductory students are not prepared for a full programming language with a professional compiler (and confusing error messages). Therefore ProfessorJ presents three language levels that are designed to gradually introduce students to a professional language. These language levels — Beginner, Intermediate, and Advanced — prevent students from accidentally stumbling across features not yet seen in class.

The manuals linked to below are for the current version of DrScheme, for other versions look at All PLT Documentation.

ProfessorJ Beginner presents basic object-oriented programming, where students learn to organize their data within class structures.

• A class must have a constructor, and may implement one interface.
• Fields must be initialized, either in the constructor or at their declaration site.
• Methods must return a value.
• Fields and methods of the current class must be accessed using this.

ProfessorJ Intermediate introduces abstraction, refinement inheritance, and mutable objects.

• Classes may be abstract, may extend other classes, and may implement multiple interfaces.
• Fields do not require initialization and may be mutated.
• Methods may be used for effects.

ProfessorJ Advanced introduces library programming, static vs. instance members, and iterative programming.

• Methods and constructors may be overloaded.
• Classes may be grouped into new library packages.