reena sahoo

• Sep 1st, 2005

 

INTERFACE 
1.all methods are abstract. 
2. does not use abstract keyword before abstract method. 
 
ABSTRACT 
1. ATLEAST ONE METHOD IS ABSTRACT. 
2. uses the abstract keyword before abstract method.

riteshyadav14@rediffmail.com

• Sep 8th, 2005

 

An abstract class may contain code in method bodies, which is not allowed in an interface. With abstract classes, you have to inherit your class from it and Java does not allow multiple inheritance. On the other hand, you can implement multiple interfaces in your class.

PavanKumar

• Jun 16th, 2006

 

hello,

The Main Difference Between the Abstract Class And the Interface are:

1)When inheriting A Interface We have to inherit all the methods of the Interface there's no other option whereas with abstract classes we can inherit the members that we are in need of.

2) The Main difference between these is that Interface cannot have any declaration within it. Just the interface has to have body of the method and the method is to be used by the classes inheriting it. Whereas in the case of Abstract Class it can have declarations (Other than the abstract method) and it can be further extended in the classes inheriting the Abstract Class.

 

 

Amar

• Aug 16th, 2006

 

Abstract Class: A class that cannot be instantiated.  An abstract class is a class that must be inherited and have the methods overridden.  An abstract class is essentially a blueprint for a class without any implementation.

Interface: Interfaces, like classes, define a set of properties, methods, and events. But unlike classes, interfaces do not provide implementation. They are implemented by classes, and defined as separate entities from classes

 

Prasant

• Sep 1st, 2006

 

An abstract class can have all concrete methods.check it.

YCS REDDY

• Mar 2nd, 2007

 

Abstract Class:
(1)it contains both abstract methods and non abstract methods
(2) object can't be created just through reference we are calling all the methods
(3) it is implemented by subclass , i.e which class is extended from this,
abstract class contains only nonabstract, this situation also code will compile fine, but problem at runtime
abstract can't be declared with  Final, Synchronized, Native, just your requirements you implement some methods in the abstract class
this class also contain Constructor

========
Interface contains all abstract methods,
all methods compulsory implemented by particular class
interface does not contain Constructor,

anooshay

 Profile Answers by anooshay 

• May 16th, 2008

 

Interface: In interface just signature of the methods are defined(means abstract meathod). there is no a single method which has body.
e.g. void add();

Abstract class: In a abstract class some method are abstract while some are concrete methods. we use abstract keyword when we declare a abstract method.
abstract keyword also used to declare class.
we cannot creat object of abstract class.
we cannot create constructor of abstract class.
e.g.
abstract class A
{
    abstract void add();
     void subtract()
     {
          int a,b;
           a=10, b=5;
           int c=a-b;
           System.out.println(c);
       }
}

ashokhullur

 Profile Answers by ashokhullur 

• Jul 22nd, 2010

 

Abstract classes can have only non abstract methods. Its not mandatory that it must have atleaset one abstract method.

Declaring class using keyword abstract is enough to make class as abstract.