Listing 9 . Answer 47. |
---|
mars.getPicture().addMessage(
"Dick Baldwin",10,20); |
Answer 46
True.
Answer 45
True.
Answer 44
True.
Answer 43
False. Code in the println method calls a method named toString on each incoming object reference and displays the string value returned by that method.
Answer 42
True.
Answer 41
False. Everything in Java is passed and returned by value , not by reference.
Answer 40
False. If there is a need to make the contents of those variables available outside the object, that should be accomplished by defining public accessor methods.
Answer 39
True.
Answer 38
False.
The default values are:
- 0 or 0.0 for numeric variables
- false for boolean variables
- null for reference variables
Answer 37
True.
Answer 36
False. When an object is instantiated, the constructor returns a reference to the new object.
Answer 35
True.
Answer 34
True.
Answer 33
True.
Answer 32
False. The code in Listing 5 instantiates one object of the World class and populates that world with two objects of the Turtle class.
Answer 31
False. The three variables declared in Listing 5 are reference variables (as opposed to primitive variables) . This means that they are capable of storing references to objects as opposed to simplybeing able to store values of the eight primitive types. It also means that they are incapable of storing values of the eight primitive types.
Answer 30
True.
Answer 29
True.
Answer 28
False. Because these variables are declared private , they can only be accessed by code contained in methods defined inside the same class (and in inner classes of the class, which is beyond the scope of this module) .
Answer 27
True.
Answer 26
True.
Answer 25
True.
Answer 24
False. The method named println that is called in Listing 1 is a method belonging to a standard system object that represents the standardoutput device (usually the command-line screen) . The purpose of the println method is to display material on the command-line screen.
Answer 23
True.
Answer 22
True.
Answer 21
True.
Answer 20
False.
In general, the type of the variable must be:
- The name of the class, or
- The name of a superclass of the class, or
- The name of an interface implemented by the class.
Answer 19
True.
Answer 18
False. The period ahead of the semicolon in Listing 4 says to search the current folder first.
Answer 17
False. The purpose of the classpath is to tell the compiler and the virtual machine where to look for previously compiled class files that the applicationneeds in order to successfully compile and execute.
Answer 16
True.
Answer 15
True
Answer 14
False. The Prob01.java and Prob01 at the ends of the two commands in Listing 4 specify the files being operated on by the compiler and the virtual machine respectively.
Answer 13
False. The Java compiler program is named javac.exe . The virtual machine is named java.exe .
Answer 12
True.
Answer 11
True.
Answer 10
True.
Answer 9
True.
Answer 8
False. The required command is shown in Listing 3 .
Listing 3 . Answer 8. |
---|
javac Prob01.java |
Answer 7
True.
Answer 6
False. The name of the application shown in Listing 1 is Prob01 .
Answer 5
True.
Answer 4
False. Java applets do not require a method named main .
Answer 3
True.
Answer 2
False. java.awt.Color belongs to the Java standard edition class library.
Answer 1
True.
Miscellaneous
This section contains a variety of miscellaneous information.
- Module name: Java3002r Review: Creating and Manipulating Turtles and Pictures in a World Object
- File: Java3002r.htm
- Published: 02/10/13
Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, youshould be aware that some of the HTML elements in this module may not translate well into PDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-