How do you use comments to improve code readability and maintainability?

1 What are comments?

Comments are lines of text that are ignored by the compiler or interpreter, but can provide useful information for the human readers of the code. Comments can be used to describe the purpose, functionality, or logic of a block of code, to mark sections or tasks, to provide references or citations, or to leave notes or reminders for yourself or other developers. Comments can be either single-line or multi-line, depending on the syntax of the programming language.

2 Why are comments important?

Comments can enhance the readability and maintainability of your code by making it more clear, concise, and consistent. Comments can help you and other developers to understand the intent and flow of the code, to identify and fix errors or bugs, and to make changes or updates without breaking the functionality or introducing new issues. Comments can also help to communicate your design decisions, assumptions, or trade-offs, as well as to document any external dependencies or sources that your code relies on.

3 How to use comments effectively?

There is no single way to use comments in code, but there are some general guidelines and principles that can help you write better comments. For instance, it's important to comment on the why behind your code, rather than the what. Additionally, focus on the high-level logic of your code and comment on any edge cases or exceptions that your code handles. It's also important to comment consistently and accurately throughout your code, as outdated or inaccurate comments can lead to confusion and errors.

4 How to avoid bad comments?

Not all comments are helpful or necessary, and some can even be detrimental to code quality. Avoid or remove obvious comments that state something already clear from the code, redundant comments that repeat what the code does, misleading comments that contradict the code, outdated comments that are no longer relevant or accurate, and too many comments that obscure the code. These issues can reduce readability and maintainability and cause confusion and errors.

5 How to use code formatting and naming conventions?

Improving code readability and maintainability goes beyond comments. Proper code formatting and naming conventions are also important. Code formatting includes layout, indentation, spacing, and punctuation, while naming conventions refer to rules or standards for naming variables, functions, classes, and other elements of the code. This can make your code more organized, consistent, and easier to understand while avoiding errors or conflicts. To make use of code formatting and naming conventions, follow the style guide or best practices of your programming language, framework, or project. Additionally, use meaningful and descriptive names for your variables, functions, classes, etc., that reflect their purpose or value. Supplement your code formatting and naming conventions with comments that provide additional information or explanation that is not obvious from the code itself; do not use comments to compensate for poor or inconsistent code formatting and naming conventions.