Developing software is a long-term, collaborative project involving thousands or millions of code lines. Remembering how every part works becomes impossible as your software scales in complexity. 

That’s why writing code documentation is crucial to describe the intricacies that make the source code work. It helps you recall why you crafted the code the way you did and makes it easy to collaborate with other developers. 

Learn how to document code with tips and best practices to improve your codebase development and maintenance. 

What’s Code Documentation?

Code documentation is any written description of how code works. It can take many forms, whether through comments within scripts or software documentation in a knowledge base. It’s essential to keep thorough documentation so you can help new team members — and even the original developer — understand the code’s complexities.

The Importance of Code Documentation

Writing and maintaining accurate software code documentation is essential to the long-term success of your product. It ensures your codebase remains as accessible and understandable as possible so everyone on the development team can interact with it as needed. Here are a few obstacles you can avoid by having proper code documentation in place:

• Indicates tech debt: If developers are putting off writing code documentation, it’s a strong indicator that they’re prioritizing speed over quality, which leads directly to tech debt — or extra work needed to fix technical issues resulting from inadequate quick fixes. 
• Hinders knowledge transfers: Without thorough technical documentation, new team members will have a steep learning curve as they try to understand all the intricacies that make your software work.
• Wastes time: If there’s no documentation to reference, developers must constantly solve problems and dig for answers to their questions, wasting vital time for everyone.

4 Benefits of Code Documentation

A codebase can consist of tens of thousands of lines of code, all stitched together by the various developers who wrote them. Here are four ways code documentation helps you write and debug software.

1. Usability

Code documentation ensures that any developer can quickly understand a code snippet’s purpose and functionality, whether they wrote it themselves or not. For instance, writing out the documentation can help the original developer fully understand their own code. Having a reference also helps them get reacquainted with it if they need to make revisions long after initial creation. It also streamlines the process of searching and debugging code by clearly labeling everything a developer may need to interact with.

2. Consistency

Writing code requires committing to various methods, functions and variables unique to your software. For example, one application could use a variable called “customer_name” while another could use “client_name.” Code documentation defines these terms so you can quickly align your understanding with peers. 

3. Clarity

Developers will refer to code documentation to clarify the software’s functionality, such as how it calculates totals or manipulates data. If written well, your code documentation will provide a precise, actionable answer everyone can use immediately. That way, team members are less likely to part ways with the best practices and style the application is following.

4. Problem diagnosis 

Comprehensive code documentation lists known issues and labels temporary solutions in the code with tags like “TODO” and “FIXME.” That way, when a developer receives an error and searches for the relevant snippet, they’ll see a comment explaining the issue they must work around.

Types of Code Documentation

Code documentation is a subset of technical documentation that’s specific to programming, so it appears in multiple unique forms. Here are four ways software developers present it:

• Code comments: The most common type of code documentation consists of several comments placed throughout a script to label blocks where you define variables, perform calculations or manipulate data. 
• README files: A README file is a separate document uploaded to the same repository where the code appears. It’s typically written either with a markdown editor or as plain text that any developer can download and read on their device.
• API documentation: Software companies often create API documentation when they know third-party developers will want to build off of their software. They publish it to an online knowledge base where they can control access and maintain it frequently.

Code Documentation Common Challenges

Code documentation is crucial to creating scalable, accessible software you can build on for years. That said, it does come with the following challenges you must account for:

• May decrease work efficiency: Writing code documentation takes time and effort, mostly from your developers, whose valuable time must also go toward creating the software.
• Can increase errors: Any mistakes in the syntax of a comment can introduce errors into your code.
• Requires knowledge of programming languages: Typically, creating documentation requires experienced developers because they understand the codebase and relevant programming languages. 
• Handles non-linear code: While you should attempt to structure your code according to the order in which it’s executed, that isn’t always possible. As a result, writing code documentation requires a counterintuitive, non-linear line of thinking.
• Considers various experience levels: The documentation must explain the code in ways that veteran and beginner programmers can understand.

6 Code Documentation Best Practices

Here are six best practices for writing code documentation that’s useful and straightforward for anyone working with your source code. 

1. Consider Your Audience

As you write code documentation, think about who will read it today, tomorrow and a year from now. That person might be you, poring over old lines of code to recall a decision you made and forgot. Leave yourself and your peers clear, obvious breadcrumbs to help everyone edit and maintain the software throughout its lifecycle.

2. Write Long-Form Descriptions

Avoid jargon or shorthand that might change over time. Instead, write thorough, long-form explanations that will make sense to anyone reading it at any point. That’s easier if you publish it in a shared knowledge base, but you’ll have to be more concise in code comments. Use multi-line comments to create lists that convey meaning efficiently.

3. Choose Helpful Tools

For in-code documentation, use professional code editors like VSCode and IntelliJ, which offer features to annotate code with comments. Then, leverage a documentation tool like Doxygen to extract code comments and shape them into a knowledge base. While you’re at it, use Scribe to automatically generate process documentation about interacting with the software.

4. Document While You Code

Don’t put off writing documentation in your code until the end of your development process. You can keep it simple for code snippets you aren’t sure you’ll keep, but don’t skip it entirely. 

5. Write Self-Documenting Code

Give variables, classes and objects human-readable names and write out calculations with clear formatting that makes the math easy to read. That way, your code comments can easily reference the code in an accessible way. For example, when creating a variable to store customer names, don’t just use “N.” Use “customer_name” instead.

6. Maintain Consistency

Follow all these best practices consistently. Turn them into habits you keep up whenever you write code, and encourage anyone you’re collaborating with to do the same. Folding effective documentation practices into your development process only works if you do it consistently.

Support Your Code Documentation With Scribe

Your code documentation becomes crucial reference material as you build on your software. It plainly reminds you how the code works, why it’s designed the way it is and how to use it. With Scribe, you can supplement your software documentation to create valuable instructions that help you transfer knowledge and document processes. 

Scribe streamlines the creation process by automatically generating step-by-step instructions with helpful annotations and screenshots. It creates embeddable modules that clearly guide readers through tasks, saving you time with onboarding new team members and sharing knowledge team-wide.

Try Scribe now for free or sign up for a demo to learn more.