Defensive Design

Defensive Design

1. Input Sanitisation - removing any unwanted characters before passing data through the program.

   • Input Validation - Checks if data meets certain criteria before passing it into the program.

2. Integrated Development Environments

   • Explorer window helps navigate through programs
   • Output Window to show the output
   • Features such as keep track of line number and character number your on
   • Error diagnostics and debugging tools help to find and fix errors.
   • Breakpoints are a common debugging tool, they stop the program on certain lines
   • A run time environment allows the code to be run quickly with IDE. This is done using start or run button.
   • Code editor is the main part where the code is written.

3. Common features of an IDE are: A translator (compiler, interpreter or both) which translates source into machine code, Auto documentation help maintenance with the program and A Graphical User Interface helps the programmer design a user interface by building it up graphically.

4. Translators

   • High Level Languages - One instruction of high level code represents many instructions of machine code and the code will work for many different machines and processors.
   • Low Level Languages - One instruction of assembly code usually only represent one instruction of machine code and usually written for one type of machine.

5. Compiler translates all source at the same time, only needed once to create the file and once comiled runs quickly but compiling takes a long time.

   • Interpreter translates and runs the source code one instruction at a time, needed every time you want to run a program and programs will run slower because code is being translated as the program is running.

6. Syntax Errors - When the compiler or interpreter does not understand something you have wrote because it doesn't follow rules or grammar.

   • Logic Errors - When the compiler or interpreter is able to run but the program does something unexpected.