Introduction to Objects - Advanced Topics in Java: Core Concepts in Data Structures - page 68

14. Write a program to read english words and their equivalent spanish words into an object
array. request the user to type several english words. For each, print the equivalent spanish
word. Choose a suitable end-of-data marker. search for the typed words using binary search.

15. a date consists of day, month, and year. Write a class to create date objects and manipulate
dates. For example, write a function that, given two dates, d1 and d2 , returns -1 if d1 comes
before d2 , 0 if d1 is the same as d2 , and 1 if d1 comes after d2 . also, write a function that
returns the number of days that d2 is ahead of d1 . If d2 comes before d1 , return a negative
value. and write a method to print a date in the format of your choice.

16. a time in 24-hour clock format is represented by two numbers; for example, 16 45 means
the time 16:45, that is, 4:45 p.m. using an object to represent a time, write a function that
given two time objects, t1 and t2 , returns the number of minutes from t1 to t2 . For example,
if the two given times are 16 45 and 23 25 , your function should return 400 .

17. Consider the problem of working with fractions, where a fraction is represented by two
integer values—one for the numerator and the other for the denominator. For example, 5/9 is
represented by the two numbers 5 and 9. Write a class to manipulate fractions. For example,
write methods to add, subtract, multiply, and divide fractions. also, write a method to reduce
a fraction to its lowest terms; you will need to find the hCF of two integers.

18. a bookseller needs to store information about topics. For each topic, he wants to store the
author, title, price, and quantity in stock. he also needs to know, at any time, how many book
objects have been created. Write java code for the class Book based on the following:

• Write a no-arg constructor, which sets the author to no author, the title to no title, and the

price and the quantity in stock to 0.

• Write a constructor that, given four arguments—author, title, price and quantity—creates a

Book object with the given values. the price must be at least $5 and the quantity cannot be
negative. If any of these conditions is violated, the price and quantity are both set to 0.

• Write accessor methods for the author and price fields.

• Write a method that sets the price of a book to a given value. If the given price is not at least

$5, the price should remain unchanged.

• Write a method that reduces the quantity in stock by a given amount. If doing so makes the

quantity negative, a message should be printed and the quantity left unchanged.

• Write an instance method that prints the data for a book, one field per line.

• Write a toString() method that returns a string that, if printed, will print the data for a

book, one field per line.

• Write an equals method that returns true if the contents of two Book objects are the same

and false otherwise.

• Write a Test class that creates three Book objects of your choice, prints their data, and

prints the number of Book objects created.