producing robust programs

producing robust programs

1. issues with not robust enough programs

   • program doesnt work
   • data compromise
   • users mad

2. defensive design

   • make program more robust
     • check for bugs
     • listen to user comments
     • protect vs malicious users
     • protect against unexpected user input
       • check if user is appropriate
         • max and min number of char
         • date of birth dd/mm/yyyy
           • numbers only
           • minimum of figures
           • max 31 max 12 max 2022
           • users age cannot exceed 130
       • validation methods
         • format check certain pattern
         • length check
         • type check correct data type
         • range check
     • maintainability
       • commenting
         • figure out logic errors easier
         • help other understand the code
       • indentation
         • easily identify what code belongs to what group
       • naming conventions
         • using constants
         • naming variables sensibly
       • formatting
         • easier to navigate
         • using functions
         • organised
     • authentication
       • username and passwords
         • has to log on to access things
         • certain people have access to certain things
         • update passwords regularly