Understanding Metrics of Code Quality

In software development, code quality is measured using various metrics that help assess the maintainability, readability, and complexity of the code. Some metrics focus on the structure and design of the code, while others relate to the development process rather than the code itself.

Exam Question

Which of the following are NOT metrics of code quality?
(choose all that apply)
A. Code Coverage
B. Class coupling
C. Cyclomatic complexity
D. Cycle time per feature
E. Depth of inheritance

Correct Answers

A. Code Coverage
D. Cycle time per feature

Explanation

Correct Answers

A. Code Coverage:
Code coverage measures the extent to which the code is exercised by tests. While it indicates test coverage, it does not directly measure code quality. High code coverage does not necessarily equate to high-quality code, as it doesn’t account for the effectiveness or relevance of the tests.

D. Cycle time per feature:
Cycle time per feature is a metric related to the process of delivering features, focusing on how long it takes to complete a feature from start to finish. This metric is more aligned with process efficiency and flow rather than the quality of the code itself.

Why the Other Options Are Code Quality Metrics

B. Class coupling:
Class coupling measures the degree of interdependence between classes in a codebase. Lower coupling generally indicates better modularity and maintainability, making it a key metric of code quality.

C. Cyclomatic complexity:
Cyclomatic complexity measures the complexity of a program by quantifying the number of independent paths through the code. Lower complexity often correlates with more maintainable and less error-prone code, making it an important code quality metric.

E. Depth of inheritance:
Depth of inheritance refers to the number of levels in an inheritance hierarchy. Excessive depth can lead to complex and harder-to-maintain code, making it a useful metric for assessing code quality.

Relevance to the PSD Exam

Understanding which metrics are directly related to code quality is essential for the PSD exam. It helps in identifying the factors that contribute to writing maintainable and high-quality code.

Key Takeaways

• Code Coverage and Cycle time per feature are not direct metrics of code quality but rather process or testing metrics.
• Code quality metrics such as class coupling, cyclomatic complexity, and depth of inheritance are crucial for assessing the maintainability and readability of code.

Conclusion

When evaluating code quality, it’s important to focus on metrics that directly measure the structure, complexity, and maintainability of the code. Understanding the difference between process-related metrics and code quality metrics is key to producing high-quality software. For more information on preparing for the PSD exam, visit our Professional Scrum Developer PSD™ Exam Prep.