Pseudocode

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Pseudocode

• Developing Your Program Logic

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What is Pseudocode

• A computer program is the representation of an
  "algorithm" (an unambiguous set of steps, in a
  particular order, which when followed will solve
  the problem)
• Pseudocode is the representation of these steps
  in "structured English"
• Steps must be clear (i.e. unambiguous)
• Order must be specified
• When the steps (i.e., instructions) are followed,
  they must produce a solution to the specified
  problem

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Why Develop Logic Using Pseudocode?

• The alternative just enter Java code?
• logic is not clear
• computer language (e.g., Java) is too detailed
  and lengthy
• focus moves to language syntax
• is not conducive to successive refinement
• Flowcharts and other design tools are suitable
  alternatives to pseudocode

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Successive Refinement

• Equally applicable whether you use pseudocode or
  flowcharting
• Start at the "top" which is a one line statement
  of your program's purpose and break it down by
  stages into greater and greater levels of detail
• Successive refinement stops when there is enough
  detail to write the program
• Each pseudocode statement or flowchart symbol is
  a basic building block (like a tinker toy)
• these are assembled into complex structures
• assembled in specific ways

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Applying Successive Refinement

• Start with a one-line statement of the problem
• Break down into 3-5 steps
• Break down each of these into 3-5 steps
• Continue this process (i.e. successive
  refinement) until each step will become one or a
  small number of Java statements

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Program (Logic) Planning

• Look at the output (desired product)
• Determine what inputs are necessary to allow the
  creation of desired output
• Design the logic (steps) to collect the input and
  build the desired output
• Often this leads to a general program logic flow
  of
• input
• processing
• output

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Advantages Derived from Using Pseudocode

• Good tool for program logic planning
• Can use to review system logic with user
• Can document logic for system maintenance