Whereas, Interface contains all abstract methods and final variable declarations.Ībstract classes are useful in a situation that Some general methods should be implemented and specialization behavior should be implemented by child classes. Interface is a pure abstract class which starts with interface keyword.Ībstract class can also contain concrete methods. The classes which implement the Interfaces must provide the method definition for all the methods.Ībstract class is a Class prefix with an abstract keyword followed by Class definition. Interface is a Java Object containing method declaration but no implementation. In other words, a subclass of a class marked Serializable passes the IS-A test for Serializable, and thus can be saved without having to explicitly mark the subclass as Serializable. An interface declaration is similar to a class declaration, with the following two very important. interface NewsPaperĭifference between an interface and an abstract class?Ībstract class is a class which contain one or more abstract methods, which has to be implemented by its sub classes. If a superclass is Serializable, then according to normal Java interface rules, all subclasses of that class automatically implement Serializable implicitly. An interface declaration creates a reference type in Java. If you think of the requirement to handle an exception as a restriction, an implementation that doesn't declare the exception is less restrictive.

interface MoveableĬlasses implements interfaces, but an interface extends other interface. A general rule of implementing and extending is you can make your new class or interface 'less restrictive' but not 'more restrictive'. Though classes in java doesn’t suppost multiple inheritance, but a class can implement more than one interface. print in ('Average speed is'+AVG-SPEED')

Interface can be nested inside another interface.

As with interface static methods, the bytecode for default methods resides in the compiled class files.

Interface can extend one or more other interface. Interfaces can also define default methods.

All methods declared inside Java Interfaces are implicitly public and abstract, even if you don’t use public or abstract keyword.

All variables declared inside interface are implicitly public static final variables(constants). Interfaces can contain only constants, method signatures, default methods, and static methods.

Methods inside Interface must not be static, final, native or strictfp.

NOTE : Compiler automatically converts methods of Interface as public and abstract, and the data members as public, static and final by default. A class can implement multiple interfaces which. To allow subtypes of non-serializable classes to be serialized, the subtype may assume responsibility for saving and restoring the state of the supertypes public, protected, and (if accessible) package fields. In this article, we'll see all those scenarios. However, in the case of nested classes or nested interfaces, it creates a class file with a name combining the inner and outer class names, including a dollar sign. When you create an interface it defines what a class can do without saying anything about how the class will do it. You can use interface names anywhere you can use any other data type name. The class implementing the interface must declare all methods in the interface with a compatible signature. The serialization interface has no methods or fields and serves only to identify the semantics of being serializable. Overview When a Java class is compiled, a class file with the same name is created.

Interface is used to achieve complete abstraction in Java. Below you can see the interface ‘Test’.Interface is a pure abstract class.They are syntactically similar to classes, but you cannot create instance of an Interface and their methods are declared without any body.