Flowcharting Skills

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Flowcharting Skills

• Visually Representing
• Process Logic

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Why Do Flowcharting?

• Economically expresses process logic A
  picture is worth a thousand words.
• Independent of implementation
• Physical or logical processes
• Supports any programming environment
• Works well for technical and non-technical
  people.

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Where does Flowcharting Fit in Systems
Development?

• During Analysis to document current process
  logic.
• During Design to communicate specified process
  logic to the implementation/construction staff.
• During Implementation to document procedures and
  processes.

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Consider Some Examples
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Problem 1

• Dave Smarsh wants to find out how much money he
  will have in his savings account after a certain
  number of years (the balance).
• He knows
• The amount he will deposit
• the interest rate he will receive
• the number of years he will be save his money
• Assumption interest is compounding
• Develop a flowchart to calculate and print the
  balance in a savings account.

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Think Like A ComputerOutline the Process

• First
• Input the Data
• Second
• Perform the Algorithm
• (Logic and Calculations)
• Third
• Output the Results

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Understand the Algorithm (Logic and
Calculations)

• After one year the balance is
• Balance Deposit (1 Rate/100)
• After the second year
• New Balance Old Balance (1Rate/100)
• New Balance Deposit (1Rate/100)2
• After year n
• Balance Deposit (1 Rate/100) n

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Order (Precedence) of Math Operations

• Programs use algebra rules
• Avoids unnecessary characters in formulas
• Complex formulas can be on one line

Z (2012)3/15
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Order Operations

• Do Everything within parentheses first.
• Inner parentheses takes precedence over outer
  parentheses
• The power operator () takes precedence over
  multiply () divide (/).
• Multiply () divide (/) take precedence over
  addition () and subtraction (-).
• Consider the formula
• Balance Deposit (1 Rate/100) n

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Order of Operations Visually

• ( ) , / , -

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Try Some Operations Precedence Problems
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Remember the Flowcharting Process

• First
• Input the Data
• Second
• Perform the Algorithm (Calculations)
• Third
• Output the Results
• How can we visualize this process?
• Use A Flowchart!!

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Flowchart Symbols

• Start/End
• Input/Output
• Process/Computation
• Decision
• Connector
• Logic Flow

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Problem 1

• Dave Smarsh wants find out how much money he will
  have in his savings account after a certain
  number of years (the balance). He knows how much
  he is going to deposit, the interest rate that he
  will receive, and the number of years that he
  will be saving his money. (Assume that the
  interest is compounding).
• Develop a flowchart to calculate and print the
  balance in a savings account.

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1 Solution
START
INPUT Deposit, Rate, No.Years
BALANCE Deposit (1 Rate/100) No.Years
PRINT Deposit, Rate, No.Years, Balance
This Program Control Structure is called
SEQUENTIAL
FINISH
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Problem 2

• Captain Beefnut, the proud owner of Beefnut
  Doughnut Shop, needs a program that will
  calculate and print bills for his customers.
• His usual price for doughnuts is 60 cents each,
  but in order to increase sales he has reduced the
  price to 40 cents each if a customer buys 12 or
  more.
• Develop this in a flowchart form.

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2 Solution
This Program Control Structure is called
SELECTION or Decision
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Consider an Extension

• Suppose Captain Beefnut wanted his program to
  repeat the algorithm if there was another
  customer bill to calculate. Add a loop which
  will accomplish this change.

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2 with loop
This Program Control Structure is called
LOOPING or ITERATION or REPETITION
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Try Some Other Flowcharting Examples

• (Then take a Quiz)