Things you need to know about Code Documentation

Clear and well-structured code documentation is essential for developers to understand and use the software design. Indeed, it can be complex to create code documentation because many variables, code blocks, and return values react to different functions. For this purpose, we need the code documentation template to get the standardized structure for application users and coders so they can perform program troubleshooting easily.

This article will explain the code documentation template, its type, benefits, best practices, and more. Let's get started.

What is code documentation?

Code documentation is a collection of documents and comments explaining how code works and how to use it. The form and size of documentation can vary. For example, some organizations use code documentation template to provide code documentation in the form of an online knowledge base, in shared files containing annotated code snippets, or within code repositories.

Why you should document your code?

Many developers need to recognize the value of documenting code. They might argue that good code is self-explanatory. However, you need the best code documentation template for maintaining a codebase because it lets developers quickly understand what the code does and how to work with it.

Also, while writing clean and clear code can make inline code comments redundant because the code is understandable in isolation, it does not provide broader, more extensive insights into how the code works, why it was built the way it was, and how to make changes to it. This is especially true considering a flow spanning multiple files or repositories. Making sure the code is clean only tells part of the story.

Clear descriptions of your code are essential for collaboration across teams, specifically for onboarding new team members and sharing code with developers from other organizations, such as customers or partners. Code documentation is also vital for the same developers who created the code, who might need to come back to it weeks, months, or years later.

Moreover, good documentation is especially needed when many developers use code inside or outside your organization. Taking the time to document the code will make their work easier, and they’ll appreciate it. Good documentation should save more time than you spend writing it—whether your own or the team’s time. In some cases, writing documentation can help identify overly complicated parts of the code and improve your architecture.

Common types of code documentation

Internal code documentation

Software engineers and developers write internal documentation for use within the organization. This type of documentation includes:

• Process documentation — provides high-level information, including product requirements and roadmaps for the development team and project manager. It can also include meeting notes and status reports.
• Developer documentation — provides details and instructions for developers and DevOps staff building, testing, deploying, or maintaining the software. It should provide technical information needed for day-to-day activities in a software project.

Examples of internal documentation include onboarding, design, and inline documents.

External code documentation

External code documentation is intended for developers or other users outside the organization who need to understand and use a product's code. A typical example is API documentation for a product's public-facing APIs.

Common types of external code documentation include:

• External developer documentation — provides basic instructions on how to use source code, integrate with a product, and leverage its developer-facing interfaces such as APIs and CLIs.
• Enterprise documentation — provides information for IT staff who need to deploy the software in the enterprise. It usually includes hardware requirements, sizing, operational requirements, and maintenance guidelines.
• Usage documentation — provides information for users who are not necessarily developers on using the product without any programmatic interface. These documents may describe the main functionalities within the product's UI.
• Just-in-time documentation — provides developers with support documentation when they need it. For example, new documentation can be added as a new feature in the form of a knowledge base article, FAQ page, or blog post.

Low-level / Inline documentation

Low-level documentation helps explain specific lines or blocks of code in isolation. Inline documentation does not explain how the line of code would work in a broader context or its role in a more complex architecture.

The most common type of low-level documentation is inline code comments. For example, a comment on a function declaration that describes what the function does, its parameters, and its return values. The comment describes a particular function in isolation, not the reason it is part of a specific flow.

Some developers don’t like writing comments but try to keep the code as readable and straightforward as possible. This is known as “self-documenting code” and can also be seen as a form of inline documentation.

High-level documentation

While low-level documentation provides minute details of the code, high-level documentation tries to paint the overall picture. It might include the code architecture’s layout, underlying business logic, and the reasons for your decisions about the code. It might also describe different repositories or the main modules in a particular repository.

This documentation is useful when working with the codebase for the first time but only offers more value. Software engineers rarely refer to high-level documentation because it only sometimes contains practical information for everyday tasks.

For example, you can describe general processes for extending Git source code in high-level documents—e.g., creating new Git commands. However, you can only explain these processes properly by describing the details and providing real examples from your code. Adding these details means the documentation is no longer high-level.

Walkthrough documentation

Walkthrough documentation fills in the gaps left by low-level and high-level documentation by providing a guided tour of the product’s codebase. It typically includes code snippets that explain points of interest on the product map as it moves from one landmark to another. It can point out recurring patterns and describe the interactions between code blocks that reside far from each other or in multiple repositories.

Code documentation challenges

Code is non-linear

Not all code follows a step-by-step paradigm, and the assembly order is not always clear when documenting code. Things that appear at the top, such as variables, may relate to the functionality at the bottom. Functions defined at the end of the code could be executed in another block of code in the middle. This becomes more complex as code flows span across multiple repositories.

The core paradigm for most technical writers is a task-based approach, where you start with steps 1, 2, and 3 and continue until the task is complete. However, this model is not usually possible with code documentation because the code can be inherently non-linear. You cannot start from the top and go down—you might have to move back and forth between multiple files and reports.

Audiences have different levels of expertise

Another common challenge is deciding what details to explain and which to skip. Some developers have a specific technical background and are highly familiar with a certain framework or pattern, while others are not.

When documenting your code, it is essential to base the documentation writing on the knowledge and requirements of your target audience, even at very different skill levels. If your audience has wildly different needs and awareness levels, you risk covering too much for experienced developers with explicit explanations or skipping important information for newer developers.

The solution is to break the documentation into separate documents for different audiences or provide an incremental discovery model, where initial information is provided first, and users can click through or expand to additional information based on their information needs.

Code documentation requires knowledge of the programming language

Developers often create code documentation, but in many cases, technical writers are asked to help create this content. Technical writers must become more familiar with the specific programming languages used in the code they document. Even if they are familiar with some programming, there might be a better language for the particular project.

To work on code documentation, technical writers and editors need to view tutorials to understand the basics of the project's code. Developers must know this challenge and collaborate with technical writers to help them understand the code.

Code documentation requires maintenance

You must ensure that the code samples work with multiple versions. For example, if you tweak a code sample, you have to go back and update the entire code in addition to your explanations for each section to keep everything in sync.

Documents can be challenging to maintain from one release to another if the documentation contains many code samples. You need to check that the code works. Keep your code separate from the narrative context to test it more regularly.

Documentation might lack traceability

Often, it isn't easy to find specific documents. The ability to track documentation throughout its lifecycle is essential for code management. Developers must be able to see the documentation's status at any given time—they must know if it has changed, been approved, or shared with other stakeholders. Traceability often requires a documentation management system.

Another issue is lost documentation: it’s not always possible to recreate lost files, or it might be time-consuming. Your organization should have a backup plan to ensure documentation remains available.

Code documentation best practices

Ensure your notes are accurate

When presenting ideas about code, start with general comments to draw attention to the most important details. You can describe things in more detail later, but short notes are enough to capture the prominent information without disrupting the flow of your document.

Consider the most salient information the reader requires—for example, definitions of essential functions or arguments, processes, or integrations important for understanding the code. Avoid long architecture or design discussions which the reader does not require in the current context.

Use long-form descriptions to explain decisions

Ideally, you can handle this step during a break from coding (but before you move on entirely to something else). Everything should be fresh when explaining your ideas, decisions, and context.

Go through your short notes and expand on them with conversation-like writing. Describe what you did as if teaching others how to do it.

Long-form does not mean endless, so stick to the point. Write the documentation in complete sentences, as if you were explaining the project to another colleague, but keep it as concise as possible.

Incorporate prerequisite information

Remember to include important prerequisite knowledge. You should ideally do this step when you have some distance from the project, but not too much. It is best to review your written documentation to ensure you have adequately filled in all the blanks. Even better, let a colleague read it and provide feedback before sharing it with the rest of the team.

Use Documentation as Code (DaC)

DaC is a way for developers to create and publish documents using the same tools and processes they use to write code. This idea has gained popularity in recent years, especially among tech companies. This process includes automatic link checking to ensure the author's changes are correct and the deployment is safe.

Using a DaC approach allows technical writers to focus on writing and makes it easy for readers to find useful, accurate information.

Conclusion

In short, we have discussed the above guide about why you need good code documentation. Clear and concise code documentation sets your organization's foundation for scalability. It also improves coding efficiency, allowing developers, testers, and designers to be on the same page. Moreover, we have also explained the apparent challenges and best practices of code documentation.