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

Virtually every coding standard bans uninitialized variables, and for very good reason. Initializing
a basic type such as ```int``` or ```char``` is straightforward, but what is the correct way of initializing a compound
type like an array or struct? A dangerous but unfortunately common practice is shown below:

#include<stdio.h>
#include<string.h>

struct TemperatureNode 
{
  double todaysAverage;
  struct TemperatureNode* nextTemperature;
};

int main() {
  struct TemperatureNode node;
  memset(&node,0, sizeof node);
  printf("Node created\n");
  return 0;
}

The problem is that ```memset```, as its name indicates, sets the bits to the given value and it does so without
***any knowledge*** of the underlying type. In C, all bits zero do not necessarily represent floating-point zero
or a **NULL pointer** constant. Initializations using ```memset``` as above result in undefined behavior for such
types.

In this lesson, we will briefly explain the idiom "Initialize Compound Types with `0`".



Initialize Compound Types with `0`

In this lesson, we will briefly explain the idiom "Initialize Compound Types with `0`".

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

Initialize Compound Types with `0`

Problem Context