Self-documenting code

In computer programming, self-documenting (or self-describing) source code and user interfaces follow naming conventions and structured programming conventions that enable use of the system without prior specific knowledge.

Objectives Commonly stated objectives for self-documenting systems include:

Make source code easier to read and understand Minimize the effort required to maintain or extend legacy systems Reduce the need for users and developers of a system to consult secondary documentation sources such as code comments or software manuals Facilitate automation through self-contained knowledge representation

Conventions Self-documenting code is ostensibly written using human-readable names, typically consisting of a phrase in a human language which reflects the symbol's meaning, such as article.numberOfWords or TryOpen. The code must also have a clear and clean structure so that a human reader can easily understand the algorithm used.

Practical considerations There are certain practical considerations that influence whether and how well the objectives for a self-documenting system can be realized.

uniformity of naming conventions consistency scope of the application and system requirements

Examples Below is a very simple example of self-documenting C code, using naming conventions in place of explicit comments to make the logic of the code more obvious to human readers.

size_t count_alphabetic_chars(const char *text) { if (text == NULL) return 0;

size_t count = 0;

while (*text != '\0')

if (is_alphabetic(*text)) count++; text++;

return count; }

Criticism Jef Raskin criticized the belief in "self-documenting" code by saying that code cannot explain the rationale behind why the program is being written or why it is implemented in such a way.

See also Autological word Code readability Comment (computer programming) Controlled natural language Literate programming Natural language programming

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Further reading