Take care to recognize the difference between implementing an abstract method and overriding a concrete method. In Java, the @Override annotation is used for both, so the terminology can be confusing.

Can have constructor. Can have abstract methods. Can have default and static methods (introduced in Java 8). Can have private methods with the implementation (introduced in Java 9). Can have any k ...

Subclasses of an abstract class must implement the abstract methods defined in the abstract class. Here is an example of an abstract class in Java: When a subclass implements the abstract methods of ...