<< Chapter < Page Chapter >> Page >
Learn how to create and manipulate Turtle objects and Picture objects in a World object using the Guzdial-Ericson multimedia library.

Revised: Sat Apr 02 13:20:42 CDT 2016

This page is included in the following Books:

Table of contents


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

Before embarking on the material in this module, you should have studied and should understand all of the material in the modules identified as Java1600 through Java1630 in the section of this book titled Essence of OOP and you should have studied and should understand allof the material in the following books:

The program described in this module requires the use of the Guzdial-Ericson multimedia class library. You will find download, installation, and usageinstructions for the library at Java OOP: The Guzdial-Ericson Multimedia Class Library .

Viewing tip

I recommend that you open another copy of this document in a separate browser window and use the following links to easily find and view the Figures and Listings while you are reading about them.


  • Figure 1 . Graphic screen output.
  • Figure 2 . Command-line output.
  • Figure 3 . Commands to compile and execute the application.
  • Figure 4 . Constructors for the World class.
  • Figure 5 . Constructors for the Turtle class.
  • Figure 6 . Constructors for the Picture class.



In this module, I will explain a program that uses Java and Ericson's media library to (see Figure 1 ) :

  • Add a picture and two turtles to a world.
  • Manipulate the turtles, their colors, and their pens.

Stated in more detail, the program will:

  • Create a Picture object from an image file and replace the default white Picture in a World object with the new Picture object.
  • Place two Turtle objects in a World object.
  • Apply a series of operations to manipulate the two turtle objects so as to produce a specific graphic output.
  • Provide accessor methods to get references to two Turtle objects and the World object.
  • Use the references to get information from the World and Turtle objects and display that information on the command-line screen.
  • Display text on a Picture in a World object.

Program output

Figure 1 shows the graphic screen output produced by this program.

Figure 1 - Graphic screen output.

Image of two turtles maneuvering in front of a background image.

Figure 2 shows the text output produced by the program on the command line screen.

Figure 2 . Command-line output.
javac 1.6.0_14 java version "1.6.0_14"Java(TM) SE Runtime Environment (build 1.6.0_14-b08) Java HotSpot(TM) Client VM (build 14.0-b16, mixed mode,sharing) Dick Baldwin.A 300 by 274 world with 2 turtles in it. joe turtle at 44, 143 heading -135.0.sue turtle at 250, 237 heading 0.0.

Questions & Answers

the properties of life
Clarinda Reply
response to the environment, reproduction, homeostasis, growth,energy processing etc.....
a complete virus particle known as
Darlington Reply
These are formed from identical protein subunitscalled capsomeres.
fabace family plant name
Pushpam Reply
in eukaryotes ...protein channel name which transport protein ...
Pushpam Reply
in bacteria ...chromosomal dna duplicate structure called
what is a prokaryotic cell and a eukaryotic cell
Matilda Reply
There are two types of cells. Eukaryotic and Prokaryotic cells. Prokaryotic cells don't have a nucleus or membrane enclosed organelles (little organs within that cell). They do however carry genetic material but it's not maintained in the nucleus. Prokaryotic cells are also one celled.
Prokaryotic cells are one celled (single celled).
Prokaryotic cells are Bacteria and Archea
Prokaryotic cells are smaller than Eukaryotic cells.
Eukaryotic cells are more complex. They are much bigger than Prokaryotic cells.
Eukaryotic cells have a nucleus and membrane bound organelles.
Eukaryotic cells are animals cells which also includes us.
Eukaryotic cells are also multicellular.
nice explaination
eukaryotic cells are individual cells .. but eukaryotes are multicellular organisms which consist of many different types of eukaryotic cells
also eukaryotic cells have mitochondria. prokaryotic cells do not
in prokaryotes only ribosomes are present... in eukaryotes mitochondria ...glogi bodies ..epidermis .....prokaryotes one envelop but eukaryotes compartment envelop....envelop mean membrane bound organelles......
prokaryotic cell are cells dat have no true nuclei i.e no cell membrane while eukaryotic cell are cell dat have true nuclei i.e have cell membrane
we have 46 pair of somatic cell and 23 pair of chromosomes in our body, pls can someone explain it to me. pls
Matilda Reply
we have 22 pairs of somatic chromosomes and one pair of sex chromosome
we have 23 pairs of chromosomes,22 pairs of somatic and one pair of sex chromosomes
23 chromosomes from dad & 23 chromosomes from mom 23 +23=46 total chromosomes
X & Y chromosomes are called sex cells, the very presence of a Y chromosome means the person is Male.
XX Female XY Male
If a Karyotype has more than 46 Chromosomes then nondisjunction occured. For example, having an extra chromosome 21 will cause Down Syndrome.
in mammal state the different vertebrae and their location in the body
Igbinigie Reply
what is a somatic cell
Senam Reply
somatic cells are body cells
somatic cell organised whole plant body part
what is biology
lilian Reply
what is biology
Dada Reply
The scientific study of life.
the study of life
the virus that causes mumps in humans is composed of a protein outer Shell containing a core of DNA
Daniel Reply
Basic science and applied science question about cancer
Joyce Reply
what are the importance of ATPs
Olatunji Reply
How can biology be studied from a microscopic approach to a global approach
Joyce Reply
The large central opening in the poriferan body is called
Chynna Reply
While the American heart association suggests that meditation might be used in conjunction with more traditional treatments as a way to manage hypertension
Beverly Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

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
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Object-oriented programming (oop) with java' conversation and receive update notifications?