2.3 Robust Programming

• Authentication • Anticipating misuse

Verifying the identity of a user.

Username, password or biometrics

Designing a program in a way that is resilient to potential misuse.

• Division by 0 • Communication error

Checking input data is sensible and in the right format.

-Type check - Range check - Presence check - Format check - Length check

Is the input the correct data type? E.g. Inputting an integer where it asks for a name.

Is the input within range? E.g. Inputting 1000 where it asks for age

Has required data been entered? E.g. Mandatory questions on google form

Correct format? E.g. DD/MM/YYYY

Does the input have the correct number of characters? E.g. 8 character password

• Make a program more robust • More user friendly • Prevents further errors later on

The process of ensuring that a program is easy to understand, modify and update.

• Use of subprograms • White space • Indentation • Relevant variable names • Comments

They give the code structure and make the purpose of the code clear.

Separates sections of code to make them visually clearer.

Makes it clear which lines of code are part of iteration statements.

Appropriate variable names mean that understanding the purpose of the variable will be easier.

Provide information about what the different parts of the program do.

To remove bugs and to ensure that the program functions as intended.

• Iterative testing • Terminal testing

Carried out while a program is being developed. The programmer writes a section of code (module) then tests it.

Carried out after all the modules are complete to ensure the code functions as it should.