What does extend class mean?
Also question is, what does it mean to extend a class?
Definition and Usage The extends keyword extends a class (indicates that a class is inherited from another class). In Java, it is possible to inherit attributes and methods from one class to another. We group the "inheritance concept" into two categories: subclass (child) - the class that inherits from another class.
Subsequently, question is, can a class extend itself? A class cannot extend itself since it IS itself, The definition of subclass is that it extends another class and inherits the state and behaviors from that class. so it is not a subclass. Inner classes are allowed to extend the outer class because those are two different classes.
In this way, when should you extend a class?
You extend a class when you want the new class to have all the same features of the original, and something more. The child class may then either add new functionalities, or override some funcionalities of the parent class.
What is the use of extends keyword?
It specifies the super class in a class declaration using extends keyword. It is a keyword that indicates the parent class that a subclass is inheriting from and may not be used as identifiers i.e. you cannot declare a variable or class with this name in your Java program.