2.3 Producing Robust Programs

Removes any unwanted characters that have been entered into a program

Checks if the data meets certain criteria before passing it through the program

Checks that data has been entered

Checks if the data is the correct length

Checks if the data is within a set range

Checks it’s in the correct format

Checks numerical data is entered correctly

Checks against a table of accepted values

Where a program confirms the identity of a user before giving them access to the full program

Code that has been well maintained is easy to edit without causing errors

Can help other programmers understand the code, as well as appropriate name for variables and sub programs

It is easy for programmers to see the flow of the program

The program goes us tested once at the end of development Everything is tested in one go

A program is tested and then changes are made as it goes through the development cycle again

Data which should be accepted by a program

Data on the limit of what should be accepted

Data that should not be accepted at all

Something which doesn’t fit the rules or grammar of the programming language

The program runs but not as expected