Gain insights into software design patterns in C, explore their implementation, discover underlying principles, and learn to build a vocabulary for better communication and coding practices.

c.tar.gz

main+customer.c

main+customer.c-copy

watches

customers

observer

Reactor

Reactor-copy

observer-copy

Software design patterns are a valuable tool in any software developer's skill set. However, most design patterns are described in the context of an object-oriented programming language such as C++ or Java. The C language is sadly absent in the pattern literature. This course is here to change that by demonstrating that it is possible to use patterns in C programs and how it adds benefits to C programmers. You will learn why design patterns are more of a communication tool than technical solutions, and how patterns let you build and share a common vocabulary that simplifies communication.

The course presents a number of patterns and explains how to implement them in C. Each pattern is introduced via the problem it solves and the domains where the pattern can be used. We also discuss the underlying design principles as well as the trade-offs when applying the pattern. Finally, the course covers a set of coding idioms that will guide you when applying design patterns in C.

Software Design Patterns in C

Identifying and exploiting commonality is fundamental to software design. By **encapsulating** and **reusing
common functionality**, the quality of the design rises above code duplication and dreaded anti-patterns
like copy-paste. This lesson dives into a design pattern that adds flexibility to common software entities
by letting clients customize and extend them without modifying existing code.

To attract and keep customers, many companies offer some kind of bonus system. In our example, a
customer is placed in one of three categories:
* Bronze customers: Get a 2 % reduction on every item bought.
* Silver customers: Get a 5 % reduction on every item bought.
* Gold customers: Get 10 % off on all items and free shipping.

A straightforward way to implement a price calculation based on this bonus system is conditional logic.

In this lesson, we will explain an example for implementing state machines.

Introduction to Pattern in C

The First-Class ADT Pattern

The State Pattern

The Strategy Pattern

The Observer Pattern

The Reactor Pattern

Idiomatic Expressions

Conclusion

Example

Control coupled customers