ITEC 120 2009spring ibarland nokie jmdymacek

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lab10a
birdwatching
loops

• Bertie the biologist was supposed to be out observing birds, but instead he went sunbathing at the beach. When the teacher asked him to turn in his log, he realized he quickly needed to forge one¹. So, he wrote the following method.

  class Bio580 { String birdWatchingLog( int numDays ) { int currentDay = 1; String messageSoFar = "Sightings:\n"; while (currentDay <= numDays) { messageSoFar += "Day " + currentDay + ": saw " + (numDays-currentDay) + " bird(s)\n"; currentDay = currentDay + 1; } return messageSoFar; } }

  Questions:
  1. What does birdWatchingLog return, when passed 3? (Don't just describe the string; give the exact string returned.) You'll want to step through the method step-by-step, to figure out exactly what it does.
  2. Give three (or or fewer) line(s) of code which you can type into BlueJ's Code Pad, so that a 30-day log is printed on the terminal window (not just in the code pad)?
• Modify the previous problem's code, so that it returns the same string plus one more line stating how many birds were seen altogether.
  Hint: you'll need to accumulate a second piece of information: the number of total birds seen so far. (What type is this info? What should you initialize it to, before you do any bird-watching? How will you update it for each journal-entry?)

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©2009, Ian Barland, Radford University Last modified 2009.Mar.31 (Tue)

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