Q 012) Abstract Class VS Interface

	INTERFACE	ABSTRACT CLASS
01)	When : When the implementation is unknown. And we only have SRS, Then Interface is a suitable choice.	When : If we know the implementation partially then we should opt for abstract class.
02 )	Method: Every method is always public and abstract weather we declare the keywords or not.	Method: Every method need not be public. In addition to abstract methods we can declare concrete methods in Abstract Class as well.
03)	Method Modifiers : Allowed: Static , final , native and strict fp.	Method Modifiers : No restrictions on abstract class methods.

	INTERFACE	ABSTRACT CLASS
04)	Variables: Every variable in interface is public , static and final  ( CONSTANTS )	Variables: No restrictions.
05 )	Variable Modifiers : Not Allowed : private,  protected, transient, volatile…	Variable Modifiers : No restrictions.
06)	Variable Initialization : Variable should be initialized at the time of declaration or will result in error.	Variable Initialization : No restriction.

07)	Instance/ Static Block : Using of Instance and static blocks will result in error.	Instance/ Static Block : We can use both instance a static block.
08)	Constructors  : Cannot use Constructors.	Constructors  : We can declare Constructors which will be executed at the time of child class object creation.
09)	Keyword : “ Implements “	Keyword :  “ Extends ”