Robust programs

Robust programs

1. robustness is the ability of a computer system to cope with errors during execution and cope with erroneous input.

   • Error
     • Runtime errors
       • may cause the program errors or the computer to crash
       • only detected when the program is executed
     • Syntax errors
       • mistakes in the way the code is written
       • Translators can only execute a program if it is syntactically correct
     • Logic errors
       • A bug in a program that causes it to run incorrectly
         • produces unintended or undesired outputs
   • Authentication
     • A coding method to check that a user is who they say they are
     • Can be physical. e.g. scanners
   • Maintainability
     • If a program is to be defensive against attacks it must be kept up to date
     • Comments and indentation

2. Testing

   • Iterative testing
     • testing the code as you create it
   • Terminal testing
     • testing is carried out when the program is finished
   • input validation
     • check made by the comment to ensure inputted data is sensible or reasonable