| ITEC 120 |
| 2012fall |
| dbraffitt ibarland |
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Delicious Sugarbomb Donuts cost 65¢ each; if you order 10 or more you get a 5% discount on all your donuts. “It pays to buy in bulk, at Bulk-o-Mart's bakery!”
First, one point: we will calculate the price of donuts not in dollars (e.g. two donuts cost 1.6 dollars), but in cents (e.g. two donuts cost 165 cents). (Think “pennies” if it helps.)
Note:Since 0.65 is less than 1, likewise 0.65¢ is less than 1¢. Don't confused a dollar with a cent!Why do we do this? The fundamental reason is that we can never charge a customer a fraction of a cent, so we shouldn't choose a data-type that allows a fraction of a cent. Using
(Another justification, if it helps:
Suppose we were opening a bakery off in the exotic kingdom of Barlandia.
The smallest coin in Barlandia is the thunk; it can't be subdivided.
One donut costs 65 thunks.
In this case, which is more appropriate:
By the way, this is all step 1 of the design recipe — decide which type best represents the data in our program!
/** Some bakery price-calcuating functions.
* @author ???
* @see http://www.radford.edu/~itec120/2012fall-ibarland/Labs/lab03a.html
*/
class Bakery extends Object120 {
/** Return the cost of a donut order, in cents.
* @param count The number of donuts being ordered.
* @return the list price for `count` donuts, including any discounts, *in cents*.
*/
// (Add your code here, *after* filling in the test cases below.)
/** Test the above function. */
static void testPrices() {
System.out.println( "0 donuts:" );
System.out.println( "Actual: " + donutOrder( 0 ) );
System.out.println( "Desired: " + ... );
System.out.println( "1 donut:" );
System.out.println( "Actual: " + donutOrder( 1 ) );
System.out.println( "Desired: " + ... );
System.out.println( "2 donuts:" );
System.out.println( "Actual: " + donutOrder( 2 ) );
System.out.println( "Desired: " + ... );
System.out.println( "10 donuts:" );
System.out.println( "Actual: " + donutOrder( 10 ) );
System.out.println( "Desired: " + ... );
System.out.println( "100 donuts:" );
System.out.println( "Actual: " + donutOrder(100 ) );
System.out.println( "Desired: " + 6175 ); // 6500¢ less 5% (325¢)
}
}
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Object120 + its docs—java.lang docs—java.util docs
| ©2012, Ian Barland, Radford University Last modified 2012.Sep.18 (Tue) |
Please mail any suggestions (incl. typos, broken links) to ibarland  radford.edu |
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