GCSE Computer Science (9-1) - 2.3 - Producing Robust Programs

What are the three ways that programmers use to protect their programs?

- anticipate how users might misuse their programs, then prevent it from happening - ensure their code is well maintained - reduce the number of errors in the code through testing

What is a Look-up table?

- check the data against a table of acceptable values

What is a Presence check?

- checks the data has actually being entered

What is a Format check?

- checks the data has the correct format

What is a Length check?

- checks the data is the correct length

What is a Range check

- checks the data is within a specific range

What is a Check digit?

- checks the numerical data has been entered accurately

What is maintainability?

- this is making your code easier to understand and interpret in other languages - this is done by: meaningful variable names, indentations and clear and well written comments

What is defensive design?

Defensive design helps to ensure that programs function properly.

What are the two ways you can prevent users from entering invalid data?

Input Sanitisation Input Validation

What are the types of testing?

Valid Invalid Extreme Erroneous Null

What is Input Validation?

checking if data meets a certain criteria before passing it into the program e.g. checking an email address has a @ symbol and a suitable ending.

What is Input Sanitisation?

removing any unwanted characters before passing data through the program

What is a syntax error?

when the compiler or interpreter doesn't understand something you've typed because it doesn't follow the rules or grammar of the programming language

What is a logic error?

when the compiler or interpreter is able to run the program but the program does something unexpected