Practical C Programming, 3rd Edition

Chapter 23. Programming Adages

Second thoughts are ever wiser.

—Euripides

General

• Comment, comment, comment. Put a lot of comments in your program. They tell other programmers what you did. They also tell you what you did.

• Use the “KISS” principle. (Keep It Simple, Stupid.) Clear and simple is better than complex and wonderful.

• Avoid side effects. Use ++ and -- on lines by themselves.

• Use the prefix version of ++ and -- (++x, --x) instead of the postfix version (x++, x--). This adage does nothing for you in C, but will serve you well when you move to C++.

• Never put an assignment inside a conditional.

• Never put an assignment inside any other statement.

• Know the difference between = and ==. Using = for == is a very common mistake and is difficult to find.

• Never do “nothing” silently.

  /* Don't program like this */ 
  for (index = 0; data[index] < key; ++index); 
  /* Did you see the semicolon at the end of the last line? */

  Always put in a comment or statement.

  for (index = 0; data[index] < key; ++index) 
          continue;

Design

• When designing your program, keep in mind “The Law of Least Astonishment,” which states that your program should behave in a way that least astonishes the user.

• Make the user interface as simple and consistent as possible.

• Give the user as much help as you can.

• Clearly identify all error messages with the word “error,” and try to give the user some idea of how to correct his problem.

Declarations

• Put one variable declaration per line, and comment them.

• Make variable-names long enough to be ...