Ralph Johnson - Author - Software-Pattern.org

Ralph E. Johnson is a Research Associate Professor in the Department of Computer Science at the University of Illinois at Urbana-Champaign. He is a co-author of the influential computer science textbook Design Patterns: Elements of Reusable Object-Oriented Software, for which he won the 2010 ACM SIGSOFT Outstanding Research Award.

Strategy

Behavioral Pattern

The strategy pattern is used to create an interchangeable family of algorithms from which the required process is chosen at run-time.

Template Method

Behavioral Pattern

The template method pattern is used to define the basic steps of an algorithm and allow the implementation of the individual steps to be changed.

Visitor

Behavioral Pattern

The visitor pattern is used to separate a relatively complex set of structured data classes from the functionality that may be performed upon the data that they hold.