An abstract method specifies behavior but no implementation. Example: In the Number class, intValue, longValue, ... are abstract. public ... ... <看更多>

A concrete example of an abstract class would be a class called Animal. You see many animals in real life, but there are only kinds of ... ... <看更多>

Here is an example of an class that extends an abstract class that implements two interfaces: (java) interface MyInterface1 { string getValue1(); } ... ... <看更多>