Java Reference
In-Depth Information
Display 14.3
Golf Score Program
(part 1 of 2)
1
import
java.util.ArrayList;
2
import
java.util.Scanner;
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public class
GolfScores
4{
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/**
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Shows differences between each of a list of golf scores and their average.
7
*/
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public static void
main(String[] args)
9
{
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ArrayList<Double> score =
new
ArrayList<Double>();
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System.out.println("This program reads golf scores and shows");
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System.out.println("how much each differs from the average.");
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System.out.println("Enter golf scores:");
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fillArrayList(score);
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showDifference(score);
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}
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/**
Parameters of type
ArrayList<Double>()
are
handled just like any other class parameter.
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Reads values into the array a.
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*/
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public static void
fillArrayList(ArrayList<
Double
> a)
21
{
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System.out.println("Enter a list of nonnegative numbers.");
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System.out.println("Mark the end of the list with a negative number.");
24
Scanner keyboard =
new
Scanner(System.in);
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double
next;
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int
index = 0;
Because of automatic boxing, we can treat
values of type
double
as if their type were
Double
.
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next = keyboard.nextDouble();
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while
(next >= 0)
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{
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a.add(next);
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next = keyboard.nextDouble();
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}
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}
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/**
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Returns the average of numbers in a.
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*/
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public static double
computeAverage(ArrayList<
Double
> a)
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{
39
double
total = 0;
A for-each loop is the nicest way to
cycle through all the elements in an
ArrayList
.
40
for
(Double element : a)
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total = total + element;
(continued)
