Confirm that you are not a robot by entering your phone numberDownload the selection for free I confirm my consent to the processing of personal data However, an abstract class does not always contain abstract methods. However, if they are used, they must be declared and must be abstract. The following code will throw a compilation error: 1 2 3 public class GraphicObject { abstract void draw(); } In the case when a class inherits from an abstract one, then you need to add a description of all the abstract methods of the parent class.
If some of its such methods are not Albania Email List implemented, then the derived class will also be abstract. Object-oriented programming: essence and objectives Read also Object-oriented programming: essence and objectives More details Interface methods that are not declared statistical or are not statistical by default (the static and default operators, respectively) are also abstract. But interface methods are usually not written abstract, so that less code needs to be done.
It turns out that they are abstract, but this is not shown explicitly. However, it is possible to add abstract without causing a compilation error. Differences between abstract and concrete classes For the former, it is impossible to create instances (for specific classes, it is possible). Extending other classes, implementing abstract methods, and subsequent inheritance are the main purposes of abstract classes. Differences between abstract and concrete classes Also, concrete models do not have constructors, but abstract ones can have them, provided that they are called directly from subclasses.