COMP 102 Programming Fundamentals I

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COMP 102Programming Fundamentals I

• Presented by Timture Choi

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Loops

• Logically controlled loops
• Pre-test loop
• while loops
• Post-test loop
• do-while loops
• Counter-controlled loops
• for loops

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The while Statement

• Use a Boolean expression
• To control the continuity of an iteration rather
  than a counter
• Syntax
• while (condition fulfilled)
• action
• Operation
• Repeat the action
• Until (condition false)

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The do-while Statement

• Syntax
• do action
• while (condition fulfilled)
• At least do action once
• Operation
• Execute action
• Evaluate condition
• if (condition true)
• Repeat the action
• else
• Exit the loop

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The for Statement

• Used the loop variable
• To control the number of times the iteration
  executes
• Syntax
• for (initialization condition update)
• action
• E.g.

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Nested Loops

• Loops within loops
• Nested if

for (initialization condition_1 update)
while (condition) action_1
action_2
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Stop a Loop

• break
• Terminate a loop
• Execute the next statement followed with the loop
  statement
• continue
• Terminate the current iteration
• Transfer the control to the statement which
  contains the controlling expression of the loop

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Forever Loop

• Structure
• while (true)
• action
• break
• Should associated with break

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for vs while

• while loop
• Provide a more flexible way of iteration than a
  for loop
• for loop
• Provide a more efficient way for loop execution

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Increment/Decrement

• / --
• Special operators for incrementing / decrementing
  an integer by 1
• E.g.
• j k
• j k
• k k 1
• j --k
• k k 1
• j k

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SUMMARY

• By the end of this lab, you should be able to
• Implement loops
• for/while statement
• Stop a loop
• Distinguish between pre-/post-increment