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True or False? A class must be declared abstract if it contains two or more abstract method declarations.
True or False? If a class inherits an abstract method, either the subclass must be declared abstract, or it must provide a concrete overridden version ofthe inherited abstract method.
True or False? The primary purpose of a constructor is to assist in the initialization of the state of an object , which depends on the values stored in its variables.
True or False? The default version of the toString method is defined in the class named Class .
True or False? There is an overloaded version of the println method that requires an incoming parameter of type Object . When that version of the method is called, it calls the toString method on the incoming object reference and displays the string that is returnedby the toString method. If the toString method belonging to the object has not been overridden, the default version of the toString method will be executed and the string that will be displayed is the string returned by that default version. The toString method can be overridden to cause the string that is displayed to be moreappropriate for the object. The toString method can be overridden only once in the class hierarchy.
What is the meaning of the following two images?
This image was inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at the same time.
The image is also an example of the kinds of things that we do in my course titled ITSE 2321, Object-Oriented Programming.
This image was also inserted for the purpose of inserting space between the questions and the answers.
False. The toString method can be overridden by every class that inherits it.
False. The default version of the toString method is defined in the class named Object .
True.
True.
False. A class must be declared abstract if it contains one or more abstract method declarations.
True.
True.
False. The same abstract method can be overridden in different ways in different subclasses. In other words, the behavior of the overridden version canbe tailored to (be appropriate for) the class in which it is overridden.
True.
False. An abstract method has no body. Therefore, it is incomplete, has no behavior, and cannot be executed.
True.
False. Listing 1 produces the output shown in Figure 2 except that the numeric values may vary from one run to the next. Note that the toString method is not overridden in Listing 1 .
Figure 2 . Output from code in Listing 1 . |
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Java3008r
DickJava3008rMyClass@4f1d0d
2727 |
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Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
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