Homework 9

Due Thurs, Jan 20, 18:00

Part I

Exercise 1: (4 points)

Create a class HourlyWorker that implements the Worker interface:

include a reasonable set of constructors
define the methods required by the interface

The hourly worker gets paid the pay rate for each hour up to and including 40.
For every hour worked over 40 hours, s/he gets paid 1.5 times the pay rate.
For example, 50 hours of work should earn 55 times the pay rate.

define toString
use the HOURS_IN_WEEK constant defined in the Worker interface

Write a junit test class HourlyWorkerTest.java with at least 3 tests that make sure that the computePay method returns the correct amount for hours worked (<40, ==40, >40).

Part II

For this part, you will create a class to represent German regular verbs with methods to return the word forms needed to conjugate in the present tense (1st, 2nd, 3rd singular and plural forms), and to return the past participle. Your class will be able to deal with the special cases of words ending in "ier", "t", and "d".

Exercise 2: (6 points)

German verbs are conjugated in the present tense by adding endings to the stem (e, st, t, en, t, en).
The past participle is usually formed by adding the prefix "ge" and the suffix "t" to the stem:
gespielt

Exceptions:
If the stem ends with "d" or "t":

An extra "e" is inserted before the ending for the du, er/sie/es, and ihr forms when conjugating:

du arbeitest
er arbeitet
ihr arbeitet

An extra "e" is inserted when forming the past participle:

gearbeitet

If the stem ends with "ier":

The past participle is formed by simply adding the suffix "t" to the stem:

probiert

Summary:

	spielen (stem spiel):	probieren (stem probier):	arbeiten (stem arbeit):
ich	spiele	probiere	arbeite
du	spielst	probierst	arbeitest
er/sie/es	spielt	probiert	arbeitet
wir	spielen	probieren	arbeiten
ihr	spielt	probiert	arbeitet
sie	spielen	probieren	arbeiten

Past participle:	gespielt	probiert	gearbeitet

Create a class GermanRegVerb which extends the abstract class GermanVerb :

Include a constructor that takes the infinitive as a parameter
Implement the abstract methods required by the GermanVerb class

Notes:

Do not make any changes to the GermanVerb class
You do not need to (and should not) override or overload the conjugatePres method.

Use GermanRegVerbTest.java to test your code.
Use GermanRegVerbDemo.java to try your code with words of your own choice.

Extra Challenge (optional exercise)

German verbs are separable if they start with certain prefixes:

zusammen, fort, nach, auf, aus, bei, ein, mit, vor, weg, an, ab, zu (there may be more).

Examples:
abspielen, nachmachen, aufstehen, ausprobieren...

Separable verbs are conjugated in the present tense the same way as regular verbs, but with the prefix added at the end as a separate word.

The past participle is formed in the same way as for regular verbs, but with the prefix added at the front:
abgespielt
ausprobiert

Summary:
Notice that this table is identical to the one above, with prefixes added.

	abspielen stem: spiel prefix: ab	ausprobieren stem: probier prefix: aus	aufarbeiten stem: arbeit prefix: auf
ich	spiele ab	probiere aus	arbeite auf
du	spielst ab	probierst aus	arbeitest auf
er/sie/es	spielt ab	probiert aus	arbeitet auf
wir	spielen ab	probieren aus	arbeiten auf
ihr	spielt ab	probiert aus	arbeitet auf
sie	spielen ab	probieren aus	arbeiten auf

Past participle:	abgespielt	ausprobiert	aufgearbeitet

Modify your GermanRegVerb to handle separable verbs.

Requirements:

override the toString method (should also include the prefix if the verb is separable)
override the equals method (should also check the prefix if the verb is separable)
You do not need to (and should not) override or overload the conjugatePres method.

Hint:

use a constant array (public static final String[] prefixList) to store the list of prefixes
Make sure that prefixList starts with the longest prefixes down to the shortest ones.
use helper methods to keep your code readable

Test with GermanRegVerbTest2.java.
Use the demo program from exercise 2 to try your code with words of your own choice.

Submit the following files to Anne (javaiscl (at googlemail.com)):
HourlyWorker.java
HourlyWorkerTest.java
GermanRegVerb.java