Program Maintainability (OCR GCSE Computer Science)

Program Maintainability

What is program maintainability?

• Maintainability is used to ensure programmers can easily understand what a program is doing months or years after having first written it

• Maintainability is also used when programming as part of a large team, so each programmer working on the team understands what each section is doing

How are programs maintained?

• Commenting of code: to explain the purpose of the code in a particular section

• White space: to make each section clear and easy to see

• Indentation: to show each instance of selection and iteration and to make it clear which code belongs to which clause in the program

• Sensible variable names: so that the name explains what that variable or data structure does and to prevent confusion later in the development process

• Use of sub-programs: functions or procedures split up programs into reusable sections of code which can remove the need for duplicating code and also increase the overall structure of the code

An example of maintainability

• The first image below shows the code for a bubble sort algorithm written in Python

• The code does not include any of the maintainability features mentioned in this section

• The second image, below, is the same program however, it clearly shows the use of

  • comments

  • meaningful variable names

  • white space

  • indentation

• By including each of these, the code immediately becomes easier to

  • read

  • understand

  • debug

  • improve