What are the benefits and drawbacks of using extract method refactoring?

1 When to use extract method

Extract method is useful when you have a long or complex method that contains several different tasks or responsibilities. By extracting each task into a separate method, you can make the original method more concise, clear, and easy to understand. You can also reuse the extracted methods in other parts of the code, avoiding code duplication and increasing consistency. Additionally, extract method can help you identify and isolate the parts of the code that can be tested independently, enhancing the testability and reliability of the code.

2 How to use extract method

To use extract method, you need to identify a section of code that can be extracted into a new method. The section should have a clear and meaningful purpose, a well-defined input and output, and no dependencies on the surrounding code. You should also choose a descriptive name for the new method that reflects its functionality and intent. Then, you need to create the new method, copy the extracted code into it, and replace the original code with a call to the new method. You should also make sure that the new method has the appropriate access level, parameters, and return type. Finally, you should test the refactored code to ensure that it works as expected and does not introduce any errors or bugs.

4 Drawbacks of extract method

Extract method is not a solution that will solve all the problems in your code and it can introduce drawbacks or challenges that need to be addressed. For instance, it can increase complexity and overhead by creating more methods, parameters, and variables to manage. Additionally, it can reduce performance and efficiency by adding extra method calls, memory allocation, and context switching that could affect the execution speed and resource consumption of the code. Furthermore, it can introduce side effects or inconsistencies by changing the scope or visibility of the variables or objects used or modified by the extracted code.

5 Best practices for extract method

To use extract method effectively and avoid its pitfalls, it is important to follow certain best practices. Extract method should only be used when it adds value to the code, and not applied blindly. Additionally, meaningful and consistent names should be given to the extracted methods, which accurately describe their purpose and behavior. Parameters and return types should be chosen carefully to minimize coupling and dependency between the methods. Furthermore, comments and documentation should be used to explain the logic and functionality of the extracted methods, especially if they are complex or non-obvious. Lastly, refactor the extracted methods further if they are too long or complex, or contain other code smells that can be improved.