More on the Repetition Structure

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More on the Repetition Structure

• Tutorial 9

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Objectives

• Show the posttest repetition structure in
  pseudocode and in a flowchart
• Code a posttest loop using the C do statement
• Nest repetition structures

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Concept Lesson
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Posttest Loops

• Condition is evaluated with each repetition, or
  iteration, of the loop
• Evaluation occurs after the instructions within
  the loop are processed

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Posttest Loops
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Coding the Posttest Loop

• In the do while statement, the programmer must
  supply the loop condition to be evaluated
• Loop condition
• must be a Boolean expression (true or false)
• can contain variables, constants, functions,
  methods, arithmetic operators, comparison
  operators, and logical operators
• Programmer must also supply statements to be
  processed when loop condition evaluates to true
• If more than one statement needs to be processed,
  they must be entered as a statement block

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Syntax of the C do while Statement
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Nested Repetition Structures

• Inner loop - placed entirely within another loop,
  called the outer loop

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Nested Loops Used by a Clock
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Application Lesson
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Sample Multiplication Table for the Number 6
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IPO Chart for the Multiplication Table Problem
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Data for Desk-checking

• Data for first desk-check
• Multiplicand 6
• Answer to another table? question Y
• Data for second desk-check
• Multiplicand 2
• Answer to another table? question N

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Completed Desk-check Table for the Multiplication
Table Algorithm
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Coding the Multiplication Table Algorithm

• Multiplication table program
• requires four memory locations to store values of
  its input and output items
• Use int data type for the variables that store
• multiplicand
• multiplier
• Product
• Use String data type for variable that stores the
  answer to the another table? question

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Completed Desk-Check Table
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Summary

• Posttest repetition structure evaluate condition
  after loop body
• Pseudocode
• Flowchart
• Code using do statement
• Work with nested repetition structures
• Make sure outer loop completely contains inner
  loop