Code Refactoring – What is it and Why is it important?

Marlena Walburg

Software development is a field where good practices are particularly significant. Creating high-quality code, as well as its future maintenance, preservation, or extension, requires not only appropriate programming skills but also a suitable approach and processes. One of them is code refactoring. Regularly conducted, it can help prevent many risky situations, such as the accumulation of bugs, security holes, or large technical debt. Such a code restructuring has many other benefits besides protecting you from overspending. Refactoring is one of the key practices in software development and is an almost inevitable part of the project life cycle. It is recommended, for example, when working with the legacy code. Dive in and learn more about code refactoring.

What is code refactoring?

Code refactoring is the process of making changes that essentially don’t change functionality. The purpose of refactoring is to maintain appropriate, high-quality system organization, not to create new functionality. Thus, the process is about taking your existing code and improving it while making it more readable, understandable and clean. Refactoring is important for reducing technical debt. After all, it is much better to clean up your code early than pay for costly bugs later. Code refactoring is a good practice that makes quality assurance and debugging much smoother with cleaner code. It can help prevent errors from occurring in the future. Routine refactoring of the code positively influences its quality. It helps to keep it consistent, prevent unnecessary duplication of code and standardize the code written by several developers. 

Refactoring or rewriting? – What is the difference?

You already know that code refactoring is simply the process of restructuring existing code without changing the core functionality of the application. It is often combined with code rewriting when approaching legacy code. These are, of course, two different strategies. Contrary to refactoring, rewriting the code involves changing not only the code structure but also its functionality. In this case, the code is created from scratch. This gives a wide range of possibilities, as the initial structure of the system is not a limitation. You can introduce innovations or convert your old system to a completely new platform. Also, when the code was created by developers no longer working on the code, and it may be difficult to understand it, rewriting it from scratch may be a sensible solution. 

Rewriting code often helps to avoid errors that occurred in its original version, but it is not necessarily the case. In fact, both refactoring and rewriting serve to eliminate them. Which approach to choose depends strictly on the given application, its size and your needs. It may turn out that rewriting the entire code from scratch is unprofitable and would change the way the application works too much. As a result, its users might abandon it. If you have a platform that has not changed for years and you feel it is outdated, you may want to consider rewriting the code. It is good to consult specialists who, thanks to their experience in software development, will provide you with the right solution.    

Why is refactoring your code important?

Now that you know what refactoring is, you can probably guess that it is a process that brings many benefits. See why it is important to perform it and what you will get:

  1. Transparent code that is easier to maintain and extend – by taking care of the quality of the code, for example by refactoring, you gain greater convenience in its maintenance. Such code is also easier to extend in the future. It is very important if you plan to develop your project in the long term. Clean code will also be easier to read for developers who will not have to spend a lot of time analyzing each function or variable but will be able to understand it immediately. 
  2. Increased performance and accelerated application operation – although this is not the main purpose of refactoring, ensuring that the codebase is no longer messy can positively affect the speed of the application. Thanks to refactoring, you will remove duplicate code as well as reduce its complexity. This importance improves the work of developers. Getting rid of unnecessary elements can help increase application performance, and maintaining it will become a more convenient, smoother process.
  3. Improves the security of the application – by keeping the code in a very good condition, nurturing it, its basis becomes demanded and stable. It is also easier to understand such a code, as well as to find any security holes or errors and fix them quickly. Refactoring also helps detect such dangers much faster than in unchanged code and react in time.
  4. Helps reduce technical debt – while there is no way to avoid technical debt entirely, refactoring helps to reduce it. Scheduling regular refactoring will ensure that the code is constantly monitored and maintained, and thus the risk of deteriorating the quality of the code will be diminished. Less technical debt means getting your product to market faster, as well as better upkeep and maintenance.

Code refactoring techniques

There are a lot of techniques that help perform the successful refactoring. They describe the actual stages of refactoring and, as with any process, each method must be properly selected for the project and used with care. They can be divided into several groups:

Composing methods

A large part of refactoring is dedicated to the correct composing methods. Methods that are too long are, in many cases, the source of errors. The behaviour of the code in these methods makes it extremely difficult to understand and change due to the execution logic hidden underneath it. Composing techniques in refactoring remove code duplication, streamline methods, and facilitate future improvements.   

Organizing data

Data organization methods help you handle the data by replacing primitives with rich class functions. Also, an additional relevant result that makes classes more portable and reusable is the disentanglement of class associations.

Moving items between objects

These refactoring techniques show you how to create new classes, safely move functions between classes, and hide implementation details from public access. If you have split the functionality into different classes in an inefficient way, these refactoring methods can help you improve those structures.

Simplifying conditional expressions

These techniques work to prevent the logic of conditional expressions from getting complicated. They help to simplify them so that they will be more understandable, and they will get rid of unnecessary duplication and complexity.

Simplifying method calls

Similar to the above, these techniques make the method calls simpler and easier to understand. This, in turn, simplifies the interfaces for interactions between classes. You can add, remove and enter new parameters, and replace parameters with explicit methods and method calls.

Dealing with the generalization

This group of refactoring techniques is mainly related to moving functionality along the class inheritance hierarchy, creating new classes and interfaces, and replacing inheritance with the delegation and inversely.

Code refactoring tools

Today, many software editors and IDEs support automatic refactoring. It is possible to refactor the application code as well as the test code. The list of such editors also called refactoring browsers, is quite extensive. A few examples of it are listed below.


Eclipse is an integrated development environment that includes a basic workspace and an extensible plug-in system for customizing the environment. It is written largely in Java, and its main use is Java application development but can also be used to develop applications in other programming languages via plugins. The Eclipse SDK includes the Eclipse Java development tools, offering an IDE with a built-in Java incremental compiler and a full Java source file model. This allows for advanced refactoring techniques and code analysis.

Microsoft Visual Studio

This IDE is a tool from Microsoft. It is used to create computer programs as well as websites, web applications, internet services and mobile applications. The Visual Studio code editor supports code refactoring, including reordering parameters, renaming variables and methods, extracting the interface, and encapsulating members in properties.


Xcode is Apple’s integrated development environment for macOS. It is used to create software for macOS, iOS and any other Apple-owned instance. The changes introduced since version 2.1 included also refactoring support.

Best practices for code refactoring

Here are some good practices and tips for getting started with code refactoring:

  1. Go Agile – do you want to approach refactoring smartly and sensibly? Apply agile methods. Doing smaller, more manageable code tasks step by step and then testing them will help you maintain refactoring efficiently and effectively. It helps not only to ensure high quality but also facilitates the developer’s work. Many agile teams are introducing code refactoring as a constant, regular point in the software development cycle.  
  2. Perform frequent tests – testing in the refactoring process is necessary if you want to avoid errors or problems that will negatively affect the functionality of the system. Make sure you have the appropriate tests in place before starting the process.
  3. Refactor before adding new features – it is a good idea to refactor before updating or adding a new feature. Even if it is a time-consuming process, you will reduce the risk of reaching a large technical debt. Thus, it is a future-proof procedure that will protect you from costly repairs.
  4. Set a goal and plan of action – before you start refactoring, think about what you want to achieve with it. Is it a routine of cleaning up your code from potential errors and removing duplicates, or maybe you want to improve the readability of your code by only changing the variable names? This will have an impact on the time it takes to complete the entire process. You should properly plan the refactor and provide spare time for it. You will make sure that it is carried out efficiently and without problems and actually fulfills its task.


It is hard not to notice the enormous value of refactoring in the software development process. By constantly improving the code, working with it becomes easier. The implementation of this care process will pay off in the future with the easily extensible, clean, and readable codebase.

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