Defensive design is programming like a pessimist - assuming everything that can go wrong, will go wrong. It's like building a castle with thick walls, a moat, and guards. You don't wait for attackers - you prepare for them. This means checking inputs, handling errors gracefully, and writing code others can understand. A good programmer doesn't trust users to enter sensible data or other programmers to use functions correctly!
This introduction covers Building Software Armour within Defensive Design for GCSE Computer Science. Revise Defensive Design in 3.2 Programming for GCSE Computer Science with 15 exam-style questions and 8 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 1 of 6 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Defensive Design
What is the purpose of input validation in a program?
Describe three different types of validation check, giving an example of each.
Quick recall flashcards
Why use comments?
To explain code so others can understand and maintain it
What is authentication?
Verifying a user's identity before granting access to a system