ITEC 120 2009spring ibarland nokie jmdymacek

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lect08c
Writing helper methods

• Looking at Employee.java, we see a named constant.
  • Advantages: easy to and maintain, as opposed to numbers which seem to magically make the code work.
  • Magic numbers don't have to be just numbers; they could be Strings!
  • final: a keyword that has the compiler help enforce our notion.
  Exercise: There is another magic number which occurs in Employee.java — what is it?

• Consider calling some helper methods — max and min. See the comment in Employee.java.

  If you are more comfortable using if-else instead of calling max and min, then certainly do so.

• Using max and min, let's write intMax. See if you can do it without if-else! Added challenge: Can you do it without any local variables?

• However, suppose that max and min worked on Strings. (They don't, but we'll come back to that.) How much easier would getFirst or getThird be, for our TresAmigos exercise?

  Compare to TresAmigos_v2.java

• Exercise: Since, alas, Java doesn't provide max and min for us, we write them ourselves! Write maxString and minString.
• Write a method maxStringOf3, minStringOf3 without using if-else.
  Compare to TresAmigos_v3.java.

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©2009, Ian Barland, Radford University Last modified 2009.Mar.23 (Mon)

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