What is the difference between an abstract class and a normal class?
Abstract class can not be instantiated using new keyword.
Concrete class can be instantiated using new keyword.
Abstract class may or may not have abstract methods.
Abstract class can inherit another class using extends keyword and implement an interface..
What is a concrete class?
A concrete class is a class that has an implementation for all of its methods. They cannot have any unimplemented methods. It can also extend an abstract class or implement an interface as long as it implements all their methods. It is a complete class and can be instantiated.
Can an abstract class inherit from a concrete class?
An abstract class always extends a concrete class ( java. … If you want to instantiate it, you will have to subclass it with a concrete implementation of those abstract methods and instantiate it through the concrete class.
What is concrete class in UML?
The actual implementation code is stored in the specialized subclasses. These subclasses are known as concrete classes because they contain the solid, real-world implementation code that knows how to operate on a particular type of data. Advertisement. In the UML, you can also specify that a class may have no children.
Why would you use an abstract class?
The short answer: An abstract class allows you to create functionality that subclasses can implement or override. An interface only allows you to define functionality, not implement it. And whereas a class can extend only one abstract class, it can take advantage of multiple interfaces.
Can we inherit abstract class?
An abstract class defines the identity of a class. An interface can inherit multiple interfaces but cannot inherit a class. An abstract class can inherit a class and multiple interfaces. … An abstract class can declare constructors and destructors.