Modularity is a key principle of software development that can improve the readability, maintainability, and reusability of your code. It means breaking down your code into smaller, independent, and coherent units that can be easily understood, tested, and modified. In this article, you will learn how to make your code modular by following some best practices and applying some common programming paradigms.
One of the first steps to make your code modular is to choose a suitable level of abstraction for each unit of code. Abstraction means hiding the unnecessary details and exposing only the essential functionality of a unit. For example, if you are writing a function that calculates the average of a list of numbers, you don't need to expose how the function loops through the list or how it handles empty lists. You only need to expose the input, output, and purpose of the function. Choosing a suitable level of abstraction can help you avoid cluttering your code with irrelevant details and make it easier to read and reuse.
The Single Level of Abstraction coding principle is relevant to this concept. For instance, if you’re standardizing the capitalization of names in a batch process, the public method invoked to do this would be more maintainable if it delegates to three other methods, say, “read()”, “capitalize(),” and “write().” Instead of reading a name via “read()”, looping through the name to capitalize the appropriate characters before calling “write().”
Another important step to make your code modular is to follow the single responsibility principle, which states that each unit of code should have only one reason to change. This means that each unit of code should have a clear and specific purpose and should not perform multiple or unrelated tasks. For example, if you are writing a class that represents a person, you should not include methods that deal with sending emails or logging activities. You should separate those concerns into different classes or modules. Following the single responsibility principle can help you avoid coupling your code with too many dependencies and make it easier to maintain and test.
A simple but effective way to make your code modular is to use consistent and meaningful naming conventions for your units of code. Naming conventions are rules or guidelines that help you choose names for your variables, functions, classes, modules, and so on. For example, you might use camelCase for variables and functions, PascalCase for classes, and snake_case for modules. You might also use prefixes or suffixes to indicate the type or scope of a unit. For example, you might use g_ for global variables or _ for private methods. Using consistent and meaningful naming conventions can help you avoid confusion and ambiguity and make your code easier to understand and communicate.
To make code modular, break it into smaller units or modules with clear functions. Minimize dependencies, use interfaces for interaction, and parameterize functions. Ensure reusability, test modules independently, and document each one thoroughly. This approach fosters easier maintenance, extension, and understanding of the codebase.
Although it makes sense for any project to follow a meaningful naming convention, it has 0 to do with making the code modular.
The language in which you are coding has a lot to do with the naming conventions you should use. For instance, in a strongly typed language like Java, using prefixes, suffixes, and conventions like Hungarian Notation will likely result in code review comments from more senior developers.
A more advanced way to make your code modular is to apply design patterns and paradigms that provide solutions to common problems and scenarios in software development. Design patterns are reusable templates or structures that help you organize your code in a logical and efficient way. For example, you might use the factory pattern to create objects without specifying their exact classes or the observer pattern to notify other objects about changes in state. Design paradigms are styles or approaches that guide you on how to structure your code in a broader sense. For example, you might use the object-oriented paradigm to model your code as a collection of objects that interact with each other or the functional paradigm to model your code as a sequence of pure functions that avoid side effects. Applying design patterns and paradigms can help you improve the modularity of your code by enhancing its flexibility, scalability, and reusability.
The final step to make your code modular is to refactor your code regularly. Refactoring means improving the quality of your code without changing its functionality. It involves identifying and removing code smells, such as duplication, complexity, inconsistency, or dead code. It also involves applying or revising the previous steps, such as choosing a better level of abstraction, following the single responsibility principle, using consistent and meaningful naming conventions, and applying design patterns and paradigms. Refactoring your code regularly can help you keep your code modular by preventing it from becoming outdated, messy, or hard to modify.
The entire article forgets to cover "how to make the code modular". In particular, anything encoded in enums, even if it is covered by factories and the like, means it is not modular enough. The usage of interfaces (and allowing new implementations to be added later) to the framework/current module is very important. Also, for modular code, dealing with breaking changes (in particular, planning for them and how to avoid them) is much more important than dealing with classes that are just reused in a single project and maybe copy/adapted on a different one. You want modular code? You need to be aware that each module will evolve on its own, will be compiled on its own and maybe even deployed on its own. Or else you'll have modular/monolith.
Follow the Clean code, Domain Driven Architecture and SOLID principle to write the code. Also follow KISS and DRY principle so your code is more readable.