Single Purpose Variables

Variables serving multiple purposes create confusion and bugs. Separate them into distinct variables—use one for counts, another for error states, and clear names for each concept. This eliminates hybrid coupling and makes your code's intent explicit.

Sentinel values like -1 force a variable to mean two things: a valid result or an error flag. This hidden meaning breaks readability and causes bugs. Replace it with separate variables—one for the actual value, one for error status—with explicit error handling.

Single-purpose variables ensure each name clearly represents one concept. Maintainers instantly understand what a variable holds without decoding hidden meanings or tracking state changes. This practice applies across all languages and improves code clarity.

Refactor when a variable holds different types of data at different times—counts mixed with flags, temporary values repurposed later, or special values encoding multiple states. Each distinct concept deserves its own variable with a clear, specific name.

Yes. Single-purpose variable design is a language-agnostic best practice. Whether you code in Python, JavaScript, Java, or any other language, separating concerns into distinct variables improves readability and maintainability across your entire codebase.

Use explicit, descriptive names that reveal intent: `error_occurred` instead of reusing `result`, `retry_count` instead of `counter`. Clear naming naturally prevents variable reuse and makes code reviews catch coupling issues before they cause bugs.