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Managing program complexity: Introduction

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• Effect of Program Complexity
  • Program complexity grows VERY rapidly (exponentially) with the size of the program

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• Tricks to Manage Program Complexity
  • Modular programming: Break program up into logically functional units (each unit does a very specific and well-defined task).

    Each unit is implemented as a subroutine or function

    This technique is called modular programming and it will be illustrated in more details soon

  • Separate compilation: When you practice modular programming, you should also maintain separate files for separate program modules

  • Program structure: Use clear flow controls: avoid GO TO statements

  • Naming: Use meaningful names for types, variables and subroutines (to make program "self-documenting)

  • Variable usage: Never use a variable for more than one purpose

    NOTE: it is OK to re-use a variable for loop index

  • Misc: Avoid using programming tricks...

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• Modular Programming....
  • One of the techniques used to keep program complexity managable is modular programming

  • In modulare programming, modules with a clear and definite function are defined; and each module is implemented as a single subroutine or function

  • NOTE: a module can itself be made up of smaller clear and definite functions which themselves be implemented by a single subroutine or function.

    So in general, a functionality is implemented by a set of subroutines and/or functions (rather than a single subroutine and/or function)