An abstract class is permitted to have both concrete and abstract methods. In abstract class, no method (either concrete or abstract) can be private. The reasons are very simple and when known looks as of common sense. Let us make a list to remember. Abstract methods in an abstract class cannot be private but can …
Java interface realtime examples Summary: By the end of this tutorial "Java interface realtime examples", you know what is interface with realtime examples. Java interface realtime examples Interface differs from abstract class in that interface contains only abstract methods. All methods should be public and abstract; if just omitted by the Programmer by style, Java …
What is interface in Java with realtime Example? Read More »
For better knowledge of Java interface, the explanation is given in Questions/Answers form, an easy way to understand fast. 1. What is an interface in Java? a) An interface contains only abstract methods (not even one concrete method). b) It differs from abstract class in that abstract class can contain concrete methods also. 2. Can …
Why Java interface required A full discussion with Example? Read More »
interface reference variables It is stated in my earlier posting Can you create instance of interface? that we cannot create objects of interfaces but possible as an inner class. Now the present question is can we create interface reference variables and if permitted what is the use of these reference variables as interface does not …
Difference Abstract class Interface Summary: By the end of this tutorial" Difference Abstract class Interface", you will be comfortable to their differences. Introduction A novice feels why both abstract class and interface are required in Java as an abstract class can contain all abstract methods also. The main difference just on the face is Interface …
Java Made Clear: Difference between Abstract class Interface Read More »
No, it is not possible. Designers did not provide a way. Of course, it is of common sense also. Because interface contains only abstract methods and as abstract methods do not have a body (of implementation code), we cannot create an object. Suppose even if it is permitted, what is the use. Calling the abstract …
Summary: At the end of this tutorial, you will be comfortable with Multiple Interfaces Implements usage. Looks difficult at the beginning, but put some patience and start reading. Do some small programs to understand still better. This is required for a Developer. Any doubts may be forwarded to me. As Java does not support direct …
Extend Multiple Classes Java Summary: At the end of this tutorial you will understand the usage of Extend Multiple Classes Java in the code. We know earlier that Java does not support multiple inheritance but supports partially through interfaces. After extends there must be only one class of either concrete (non-abstract) or abstract. After implements …
These are two different concepts which can be explained easily by a novice having a little bit knowledge of abstract classes and interfaces. It is advised to read abstract classes before going through this topics. It gives thorough understanding of abstract classes where some concepts you may not aware of, perhaps. Before going further let …
Abstract class constructor and Interface abstract Read More »
We know earlier, Java does not support multiple inheritance, basically. But to support multiple inheritance, partially, Java introduced "interfaces". An interface is not altogether a new one for us; just it is a special flavor of abstract class where all methods are abstract. That is, an interface contains only abstract methods. Syntax of multiple inheritance …
