چند نکته در مورد اینترفیس در جاوا

• directly JVM knows that the method of the interface is abstract and it is  no need to write abstract before the method in the interface.
• we can create reference variable of an interface, but we can not  create the object of an interface using a new keyword.
• interface can not contain constant. They are "static final" by default.
• one interface also can Extend other interfaces.
• to the reference of an interface we can store the object of the class that implements the interface.
• also we can store the reference variable of the interface to the reference
  variable of the class by using of type casting concepts.
• interface dose not have constructor==> we can not create object of it.