What is a programming rule?

• naming rules: they define the way identifiers are used in an application to make the code easier to read and help to detect errors.
  Example: all constant names must be in UPPERCASE.
• portability rules: they identify language constructs in the code that can induce a different behavior depending on the operating system or the microprocessor being used.
  Example: two floating numbers shouldn't be compared using strict equality.
• rules that protect from language difficulties.
  Example for the C language: do not mix up the "=" used for affecting a value and the "==" used to compare.
• presentation rules that make the code easier to read.
  Example: write a single instruction per line.
• rules that make application maintenance easier.
  Example: when writing code in C, C++ or Java, use opening and closing braces in the if and then blocs of a test.
• rules that limit code complexity.
  Example: limit the complexity of expressions to 4 operators at the most.
• rules that allow better code structure.
  Example: declare shared variables in a header file.

Checking programming rules

Standard programming rules

• MISRA C: a set of rules initially conceived for the automobile industry and now widely used.
• MISRA C++: a version of the MISRA C rules adapted to the C++ language
• Scott Meyers rules: these rules are described in the following books:
  
  • "Effective C++: 50 Specific Ways to Improve Your Programs and Designs" (Addison-Wesley, second dition, 1997, ISBN: 0-201-92488-9)
  • "More Effective C++: 35 New Ways To Improve Your Programs And Designs" (Addison-Wesley, first edition, 1996, ISBN: 0-201-63371-X).