Single Purpose Variables

Single-purpose variables eliminate hybrid coupling by ensuring each variable represents one concept. Instead of using special values like `-1` for errors, create separate variables: keep `page_count` for counts and add `processing_failed` as a boolean flag. This prevents misinterpretation and makes code behavior predictable.

Identify variables encoding multiple states through special values or implicit conventions. Replace them with distinct, purpose-specific variables with clear names. For example, split a `status` variable holding both data and error signals into `result_value` and `error_occurred`, improving readability and reducing logic errors.

Reusing `temp` across unrelated purposes creates confusion about what it currently holds. A reader or maintainer may misinterpret its state, leading to incorrect logic. Dedicated variables for counting, configuration, and processing make intent explicit and prevent accidental misuse.

Single-purpose variables reduce cognitive load by making each variable's role obvious. Code reviewers and future maintainers understand intent immediately without tracing special interpretations. Naming becomes straightforward, documentation clarity improves, and refactoring becomes safer.

Yes. Single-purpose variables apply across counting loops, configuration management, error handling, and temporary data processing in any language. The principle is language-agnostic: separate concerns into distinct variables instead of overloading meaning onto one.