YouTube Link: https://youtu.be/jJ8L3SeFy_E **Java, J2EE & SOA Certification Training - https://www.edureka.co/java-j2ee-training-course ** This Edureka PPT on "Interface on Java" will provide you with detailed knowledge about Java Interface and also cover some real-time examples in order to provide you a better understanding of the functionality of Java Interface. This PPT will cover the following topics: What is an Interface? Why do we need an Interface? Practical examples on Interface Interface Nesting Difference between Class and Interface Advantages and Disadvantages of Interface Key Points on Interface. Practical Examples of Interface on Key Points Follow us to never miss an update in the future. YouTube: https://www.youtube.com/user/edurekaIN Instagram: https://www.instagram.com/edureka_learning/ Facebook: https://www.facebook.com/edurekaIN/ Twitter: https://twitter.com/edurekain LinkedIn: https://www.linkedin.com/company/edureka Castbox: https://castbox.fm/networks/505?country=in

1. Copyright © 2017, edureka and/or its affiliates. All rights reserved.

2. HOW TO DECLARE JAVA INTERFACE?
DIFFERENCE BETWEEN INTERFACE AND CLASS
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WHAT IS A JAVA INTERFACE?
WHAT IS AN INTERFACE?
ADVANTAGES AND DISADVANTAGES OF JAVA INTERFACE
WHY DO WE NEED A JAVA INTERFACE?

3. WHAT IS AN INTERFACE?
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4. • An interface is a shared boundary across which
two or more separate components of a computer
system to exchange information.
• The exchange can be between software,
computer hardware, peripheral devices, humans,
and combinations of these.
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WHAT IS AN INTERFACE?

5. WHAT IS A JAVA INTERFACE?
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6. Interface is an abstract type that is used to specify a
behavior that all the classes must implement.
WHAT IS A JAVA INTERFACE?
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7. WHY DO WE NEED A JAVA INTERFACE?
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8. We need Java Interface to overcome the problem of
Multiple inheritance.
WHY DO WE NEED A JAVA INTERFACE?
Super Class
Class C
Class A Class B
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9. WHY DO WE NEED A JAVA INTERFACE?
Airplane
Passenger Airplane Cargo Airplane
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10. WHY DO WE NEED A JAVA INTERFACE?
Airplane
Passenger Airplane Cargo Airplane
Commercial Airplane
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11. WHY DO WE NEED A JAVA INTERFACE?
Passenger Airplane Cargo Airplane
Commercial Airplane
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12. WHY DO WE NEED A JAVA INTERFACE?
Passenger Airplane Cargo Airplane
Commercial Airplane
IMPLEMENTING
INTERFACES FOR
CARGO PLANE
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13. HOW TO DECLARE A JAVA INTERFACE?
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14. HOW TO DECLARE A JAVA INTERFACE?
interface <interface_name> {
// declare constant fields
// declare methods that abstract
// by default.
}
SYNTAX TO DECLARE AN INTERFACE?
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15. CLASS V/S INTERFACE
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16. Interface supports Multiple Inheritance
Class does not support to Multiple inheritance
Multiple Inheritance
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17. Interface does not have Data Members
Class includes Data Members
Data Members
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18. Interface does not have Constructors
Class includes Constructors
Constructors
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19. Interfaces Includes Incomplete Member(Signature Member)
Class Includes both Complete(Abstract) and Incomplete
Members.
Complete and Incomplete Members
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20. www.edureka.co
Interface does not have Access Modifiers
Class includes Access Modifiers
Access Modifiers

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No member of an Interface is Static
Class has complete Members of the class as Static.
Static Members

22. ADVANTAGES AND DISADVANTAGES
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23. ADVANTAGES AND DISADVANTAGES
• Through interfaces we can implement
multiple inheritance in java.
• Interfaces function to break up the
complex designs and clear the
dependencies between objects.
• Interfaces makes your application
loosely coupled.
ADVANTAGES
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24. ADVANTAGES AND DISADVANTAGES
DISADVANTAGES
• Java interfaces are slower and more
limited than other ones.
• Interface should be used multiple
number of times else there is hardly any
use of having them.
• Through interfaces we can implement
multiple inheritance in java.
• Interfaces function to break up the
complex designs and clear the
dependencies between objects.
• Interfaces makes your application
loosely coupled.
ADVANTAGES
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25. KEY POINTS
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26. KEY POINTS
CAN WE INSTANTIATE AN INTERFACE?
We cannot create the object of an
interface. Hence, We can’t instantiate an
interface in Java.
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27. KEY POINTS
ABSTRACTION
Interface provides full abstraction as none
of its methods have body.
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28. KEY POINTS
IMPLEMENTING AN INTERFACE?
• The Keyword Implement is used by a class to implement
an Interface.
• The method in an Interface must be provided as Public
before implementing it in any Class.
• Class must implement all the methods declared in an
Interface, or else it must be declared as an Abstract Class.
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29. KEY POINTS
ACCESS MODIFIERS IN AN INTERFACE
• Interface cannot be declared as private, protected or transient.
• All the interface methods are by default abstract and public.
• Variables declared in interface are public, static and final by
default.
• Interface variables must be initialized at the time of declaration
otherwise compiler will throw an error.
• Inside any implementation class, you cannot change the
variables declared in interface.
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30. KEY POINTS
EXTENDING AN INTERFACE
• An interface can extend any interface but cannot implement it.
• A class can implement any number of interfaces.
• If there are two or more same methods in two interfaces and a
class implements both interfaces, implementation of the method
once is enough.
• A class cannot implement two interfaces that have methods with
same name but different return type.
• Variable names conflicts can be resolved by interface name.
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31. Copyright © 2019, edureka and/or its affiliates. All rights reserved.

32. www.edureka.co