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Learn about interfaces, arrays of type Object, etc.

Revised: Sun Apr 03 17:27:47 CDT 2016

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This module is one of a series of modules designed to teach you about Object-Oriented Programming (OOP) using Java.

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  • Figure 1 . Command line output for Prob05.



In this module, you will learn about :

  • Interface definitions
  • Implementing an interface in a class definition
  • Defining interface methods in a class definition
  • Storing references to new objects in elements of an array of type Object
  • Casting elements to an interface type in order to call interface methods
  • Parameterized constructors
  • Overridden toString method

Program specifications

Write a program named Prob05 that uses the class definition shown in Listing 1 to produce the output shown in Figure 1 on the command line screen.

Figure 1 . Command line output for Prob05.
Prob05 Put your first name herePut your last name here -18 -17 -16-17 -17 -17 -12 -12 -12

No graphic output images required

There are no graphic output images required by this program. Therefore, it can be compiled and executed without a requirement to have Ericson's medialibrary on the classpath.

Required text output

The output, which appears on the command line screen, consists of the six lines of text shown in Figure 1 .

Because the program generates random data for testing, the actual values will differ from one run to the next. However, in all cases:

  • The values in the first row of numbers will be a sequence of consecutive integers in increasing algebraic order from left to right.
  • All three values in the second row of numbers will match the value of the center number in the first row of numbers.
  • All three values in the third row of numbers will be algebraically five greater than the values in the second row of numbers.

New classes

You may define new classes as necessary to cause your program to behave as required, but you may not modify the class definition for the class named Prob05 shown in Listing 1 .

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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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