Reusable code

Check if your code is reusable. If reusing your code requires a lot of effort, nobody will use it.

Reusable code is code that can be easily used in multiple places without extra effort. If reusing your code is painful, developers will copy-paste or write it again, which leads to duplication, bugs, and maintenance headaches. Strive for modular, clear, and configurable components.

For example, instead of hardcoding a file path or format:

public class ReportGenerator {
    public void generateReport(List<String> data) {
        // always writes to "/tmp/report.txt"
        try (PrintWriter writer = new PrintWriter("/tmp/report.txt")) {
            for (String line : data) {
                writer.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Refactor it to be reusable:

public class ReportGenerator {
    public void generateReport(List<String> data, Path outputFile) {
        try (PrintWriter writer = new PrintWriter(Files.newBufferedWriter(outputFile))) {
            for (String line : data) {
                writer.println(line);
            }
        } catch (IOException e) {
            throw new RuntimeException("Failed to generate report", e);
        }
    }
}

Now it’s flexible - you can generate reports to any location without changing the code.

Practical habits for reusability:

Accept parameters instead of hardcoding values.
Keep methods focused on a single task.
Avoid tight coupling with other classes or frameworks.
Provide clear and consistent interfaces.
Make it easy to extend or customize without modifying the core logic.

Every commit should ask: “Could someone use this in a different context easily?” If not, consider refactoring. Reusable code saves time, reduces bugs, and improves consistency across your codebase.