---
title: No Unused Variables
impact: LOW
impactDescription: reduces confusion and identifies potential logic errors
tags: cleanup, quality, maintenance
---

## No Unused Variables

Variables that are declared but never used often indicate a typo or a forgotten piece of logic.

**Incorrect (unused variables):**

```ruby
def calculate(a, b)
  result = a + b
  temp_data = fetch_additional_info # Fetched but never used
  result
end
```

**Correct (clean variables):**

```ruby
def calculate(a, b)
  a + b
end
```

**Tools:** RuboCop (`Lint/UselessAssignment`)
---