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TUSHAR KADAM answered on November 28, 2020 Popularity 10/10 Helpfulness 3/10

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--Interface in java-
-used to specify the behaviour of a class
-blueprint of a class
-contains static constants and abstract methods
-mechanism to achieve 100% abstraction
-used to achieve abstraction and multiple inheritance in java
-interfaces can have abstract methods and variables, cannot have a method body.

-represents IS-A relationship
-cannot be instantiated just like abstract class
-since java 8, can have default and static methods

-to declare, use interface keyword
-all fields public, static and final by default

-class that implements interface must implement all the methods from interface
-to implement interface to a class, use implements keyword

-syntax- 
    interface InterfaceName
    {
        //declare constant fields
        //declare methods that is abstract by default
    }
    
-we save interface also with .java extension

-uses of interface-
1.to achieve total abstraction
2.to achieve multiple inheritance
3.to achieve loose coupling

-Note- The java compiler adds public and abstract keywords before the interface
method. Moreover, it adds public, static and final keywords before data members.

-eg.
    //Shape.java
    public interface Shape
    {
        void draw();
    }

    //Rectangle.java
    class Rectangle implements Shape
    {
        public void draw()
        {
            System.out.println("drawing rectangle");
        }
    }
    
-class extends another class, interface extends another interface,
    but class implements an interface

--multiple inheritance in java by interface
-class implements multiple interfaces, or interface extends multiple interface known as multiple inheritance
-
-Interface inheritance-
-interface extends another interface

-New features added in Interfaces in JDK 8-
-1.default methods inside an interface:
-to add new function in existing interface, old code will not work as classes not implemented those new functions
-so with help of default implementation, we will give a default body for newly added functions,
-then old codes will still works.
-defaults methods need not override inside implementation class, but if you want you can.

-2.Static methods inside interface:
-static methods in interface can be called independently withour an object.
-these methods are not inherited, call static method with help of interface name

    //Intr.java
    interface Intr
    {
        //abstract method
        void method1();
        
        //default method
        default void method2()
        {
            System.out.println("inside method2");
        }
        
        //static method
        static void method3()
        {
            System.out.println("inside method3");
        }
    }
    
    //IntrImpl1.java
    class IntrImpl1 implements Intr
    {
        public void method1()
        {
            System.out.println("inside method1 of IntrImpl1");
        }
    }
    
    
    //Main.java
    class Main
    {
    public static void main(String[] args)
    {
        IntrImpl1 i1 = new IntrImpl1();
        i1.method1();   //abstract method
        i1.method2();   //default method
        Intr.method3(); //static method cannot inherited, called with interface name
    }
    
    }
    
---------------------------------------------------------------------

--marker or tagged interface in java-
-interface has no member
-eg. Serializable, Clonable, Remote etc.
-used to provide some essential information to the JVM that JVM may perform some useful operations.

----------------------------------------------------------------------

--Difference between Abstract class and Interface-

Abstract class                      Interface
1. An Abstract class can have
abstract and non-abstract
methods.
                                    An Interface can have only abstract  methods. Since
                                    Java 8, it can have default and static methods also.
2. An Abstract class doesn't
support multiple inheritance. .
                                    An Interface supports multiple inheritance. .
3. An Abstract class can have
final, non-final, static and 
nonstatic variables .
                                    An Interface has only static and final variables .
4. An Abstract class can provide
the implementation of interface.
.
                                    An Interface can't provide the implementation of
                                    abstract class .
5. An abstract class can extend
another Java class and implement
multiple Java interfaces.
                                    An interface can extend another Java interface only.
6. A Java abstract class can have
class members like private,
protected, etc.
                                    Members of a Java interface are public by default.

Popularity 10/10 Helpfulness 3/10 Language java

Source: Grepper

Tags: interface java

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Contributed on Nov 21 2022

TUSHAR KADAM

0 Answers Avg Quality 2/10

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what is interface

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Interfaces specify what a class must do. 
It is the blueprint of the class.
It is used to achieve total abstraction. 
We are using implements keyword for interface.

Basic statement we all know in Selenium is
WebDriver driver = new FirefoxDriver();
WebDriver itself is an Interface.
So we are initializing Firefox browser
using Selenium WebDriver.
It means we are creating a reference variable
of the interface and creating an Object.
So WebDriver is an Interface and
FirefoxDriver is a class.

Popularity 10/10 Helpfulness 3/10 Language whatever

Source: Grepper

Tags: interface inte

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Contributed on Nov 28 2020

Obedient Ocelot

0 Answers Avg Quality 2/10

interface example

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import { Component } from '@angular/core';

//Student interface
  
interface Student {
    id: number;
    name: string;
}
  
@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular';
    //Use of interface
  students: Student[] = [
    {id: 1, name: "Hardik"},
    {id: 2, name: "Paresh"},
    {id: 3, name: "Rakesh"},
  ]
}

Popularity 10/10 Helpfulness 2/10 Language whatever

Source: www.itsolutionstuff.com

Tags: interface inte

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Contributed on Jul 01 2022

Chaitanyakumar Gajjar

0 Answers Avg Quality 2/10

interface definition

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Interface Define a set of Characteristics and Behaviors 
such as 
Member Signature Only
No Implementation Details
Cannot be Instantiated

Popularity 10/10 Helpfulness 2/10 Language whatever

Source: Grepper

Tags: definition d

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Contributed on Dec 28 2021

Deepak Chakravarthy

0 Answers Avg Quality 2/10

interfaces

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class Calculator(AdvancedArithmetic):
    def divisorSum(self, n):
        temp = []
        for i in range(1, n+1):
            if n%i == 0:
                temp.append(i)
        return sum(temp)

Popularity 10/10 Helpfulness 1/10 Language python

Source: programs.programmingoneonone.com

Tags: python py

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Contributed on Aug 11 2021

Frightened Frog

0 Answers Avg Quality 2/10

interface

Comment

interface Readable
{
	public function read();
}

interface Document extends Readable
{
	public function getContents();
}
Code language: PHP (php)

Popularity 9/10 Helpfulness 1/10 Language whatever

Source: www.phptutorial.net

Tags: interface inte

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Contributed on Mar 16 2023

Bexruz Bahromov

0 Answers Avg Quality 2/10

interface

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[Exposed=(Window,DedicatedWorker,SharedWorker)]
interface XMLHttpRequestEventTarget : EventTarget {
  // event handlers
  attribute EventHandler onloadstart;
  attribute EventHandler onprogress;
  attribute EventHandler onabort;
  attribute EventHandler onerror;
  attribute EventHandler onload;
  attribute EventHandler ontimeout;
  attribute EventHandler onloadend;
};

[Exposed=(Window,DedicatedWorker,SharedWorker)]
interface XMLHttpRequestUpload : XMLHttpRequestEventTarget {
};

enum XMLHttpRequestResponseType {
  "",
  "arraybuffer",
  "blob",
  "document",
  "json",
  "text"
};

[Exposed=(Window,DedicatedWorker,SharedWorker)]
interface XMLHttpRequest : XMLHttpRequestEventTarget {
  constructor();

  // event handler
  attribute EventHandler onreadystatechange;

  // states
  const unsigned short UNSENT = 0;
  const unsigned short OPENED = 1;
  const unsigned short HEADERS_RECEIVED = 2;
  const unsigned short LOADING = 3;
  const unsigned short DONE = 4;
  readonly attribute unsigned short readyState;

  // request
  undefined open(ByteString method, USVString url);
  undefined open(ByteString method, USVString url, boolean async, optional USVString? username = null, optional USVString? password = null);
  undefined setRequestHeader(ByteString name, ByteString value);
           attribute unsigned long timeout;
           attribute boolean withCredentials;
  [SameObject] readonly attribute XMLHttpRequestUpload upload;
  undefined send(optional (Document or XMLHttpRequestBodyInit)? body = null);
  undefined abort();

  // response
  readonly attribute USVString responseURL;
  readonly attribute unsigned short status;
  readonly attribute ByteString statusText;
  ByteString? getResponseHeader(ByteString name);
  ByteString getAllResponseHeaders();
  undefined overrideMimeType(DOMString mime);
           attribute XMLHttpRequestResponseType responseType;
  readonly attribute any response;
  readonly attribute USVString responseText;
  [Exposed=Window] readonly attribute Document? responseXML;
};

Popularity 7/10 Helpfulness 1/10 Language whatever

Source: xhr.spec.whatwg.org

Tags: interface whatever wha

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Contributed on Dec 06 2023

Karla Gonzalez

0 Answers Avg Quality 2/10

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