February 2014
Beginner
1248 pages
62h 25m
English
Content preview from Java™ How To Program (Early Objects), Tenth Edition
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Declaring an Abstract Class and Abstract Methods
You make a class abstract by declaring it with keyword abstract. An abstract class normally contains one or more abstract methods. An abstract method is an instance method with keyword abstract in its declaration, as in
public abstract void draw(); // abstract method
Abstract methods do not provide implementations. A class that contains any abstract methods must be explicitly declared abstract even if that class contains some concrete (nonabstract) methods. Each concrete subclass of an abstract superclass also must provide concrete implementations of each of the superclass’s abstract methods. Constructors and static methods cannot be declared abstract. Constructors ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.