Maintainability
Computer Science: Edexcel IGCSE, topic 2.1.1
Maintainability
Maintainable code is code that can be read, understood, and fixed by other developers. There are a few best-practice techniques to help write maintainable code, including:
Comments
- Comments should be used throughout the code to:
- Explain complex processes.
- Clarify the purpose of algorithms.
- Clarify the purpose of a subroutine, as well as its parameters and return type and value.
Indentation
- It is good practice to keep indentation of code consistent throughout the code.
- When a new block of code opens, it should be indented to the right.
- When a block of code closes, it should return to the left.
- This makes code easier to read by visualising the scopes involved.
Identifier names
- Identifier names should be clear about their purpose. For example, which of the following two examples makes more sense:
- newBalance = oldBalance * INTEREST_RATE;
- a = b * c;
Code structure
- Code should be well structured through the use of subroutines.
- This allows people to identify a single subroutine that they need to reuse or work on.
Parameters vs global variables
- It is good practice to pass data around the program using parameter passing rather than using global variables.
- This is because passing parameters prevents other subroutines from unexpectedly changing the value of the variables.
Test yourself on Maintainability
What does indentation help programmers to visualise?
Which of these identifier names are most appropriate?