Asked by: Kia Fornell
technology and computing programming languages

Can we import interface in Java?

Last Updated: 21st March, 2020

39
Implementing Multiple Interfaces
If the interfaces are not located in the same packages as the implementing class, you will also need to import the interfaces. Java interfaces are imported using the import instruction just like Java classes. For instance: As you can see, each interface contains one method.

Click to see full answer.

Also question is, how do interfaces work in Java?

Java uses Interface to implement multiple inheritance. A Java class can implement multiple Java Interfaces. All methods in an interface are implicitly public and abstract. To use an interface in your class, append the keyword "implements" after your class name followed by the interface name.

Subsequently, question is, what is meant by interface in Java? An interface in java is a blueprint of a class. It has static constants and abstract methods. The interface in Java is a mechanism to achieve abstraction. There can be only abstract methods in the Java interface, not method body. It is used to achieve abstraction and multiple inheritance in Java.

In respect to this, why interfaces are used in Java?

It is used to achieve total abstraction. Since java does not support multiple inheritance in case of class, but by using interface it can achieve multiple inheritance . It is also used to achieve loose coupling.

Can an interface extend more than one interface in Java?

An interface cannot contain instance fields. The only fields that can appear in an interface must be declared both static and final. An interface is not extended by a class; it is implemented by a class. An interface can extend multiple interfaces.

Related Question Answers

Colas Ziegelaar

Professional

Can an interface have a constructor?

This is a most frequently asked java interview question. The answer is No, interface cannot have constructors. In order to call any method we need an object since there is no need to have object of interface, there is no need of having constructor in interface (Constructor is being called during creation of object).

Abdelouahad Geisendorfer

Professional

What is an interface in OOP?

Interfaces in Object Oriented Programming Languages. An interface is a programming structure/syntax that allows the computer to enforce certain properties on an object (class). For example, say we have a car class and a scooter class and a truck class.

Alasana Botias

Professional

Why do we need interface?

Interfaces are more flexible, because a class can implement multiple interfaces. Since Java does not have multiple inheritance, using abstract classes prevents your users from using any other class hierarchy. In general, prefer interfaces when there are no default implementations or state.

Fahim Virot

Explainer

Can we create object of interface?

NO we cant create an object of an Interface ,we use an Interface to hide the implementations from user. Interface contains only abstract methods and as abstract methods do not have a body (of implementation code) we can not create an object without constructor also .

Tsvetana Oczeretu

Explainer

Why is interface used?

Interfaces are useful because they provide contracts that objects can use to work together without needing to know anything else about each other. The point of interfaces is not to help you remember what method to implement, it is here to define a contract.

Liset Gottschlich

Explainer

What is Polymorphism in Java?

Polymorphism in Java is a concept by which we can perform a single action in different ways. We can perform polymorphism in java by method overloading and method overriding. If you overload a static method in Java, it is the example of compile time polymorphism. Here, we will focus on runtime polymorphism in java.

Bru Arca

Pundit

What is static in Java?

In Java, a static member is a member of a class that isn't associated with an instance of a class. Instead, the member belongs to the class itself. As a result, you can access the static member without first creating a class instance. The value of a static field is the same across all instances of the class.

Portal Creuzburg

Pundit

What is the benefit of interface in Java?

The Purpose of Java Interfaces
Interfaces are used to provide the benefits of multiple inheritance without its implementation difficulties. They allow several classes to share a standard set of methods and constants without requiring these methods and constants to be implemented by a common superclass.

Rong Menasche

Pundit

Can a method return an interface?

Methods do not return interfaces or classes. They return a reference to an instance (=object) or null (or a primitive value, but let's stick with objects). This reference is usually either stored in a variable or used to call instance methods or access instance members.

Fredric Arion

Pundit

Why abstraction is used in Java?

Abstraction is selecting data from a larger pool to show only the relevant details to the object. It helps to reduce programming complexity and effort. In Java, abstraction is accomplished using Abstract classes and interfaces. It is one of the most important concepts of OOPs.

Cian Velikin

Pundit

What do you mean by user interface?

A user interface, also called a "UI" or simply an "interface," is the means in which a person controls a software application or hardware device. Nearly all software programs have a graphical user interface, or GUI. This means the program includes graphical controls, which the user can select using a mouse or keyboard.

Chada Rujitsky

Teacher

What is object in Java?

ObjectObjects have states and behaviors. Example: A dog has states - color, name, breed as well as behaviors – wagging the tail, barking, eating. An object is an instance of a class. Class − A class can be defined as a template/blueprint that describes the behavior/state that the object of its type support.

Nayim Thompson

Teacher

What is encapsulation in Java?

Encapsulation is one of the four fundamental OOP concepts. The other three are inheritance, polymorphism, and abstraction. Encapsulation in Java is a mechanism of wrapping the data (variables) and code acting on the data (methods) together as a single unit. Declare the variables of a class as private.

Loriann Korbes

Teacher

Can we create object of abstract class?

Because it's abstract and an object is concrete. No, designers did not provide a way. Because an abstract class is an incomplete class (incomplete in the sense it contains abstract methods without body and output) we cannot create an instance or object; the same way you say for an interface.

Petronila Jaminsky

Teacher

What is implements in Java?

Difference: implements means you are using the elements of a Java Interface in your class. extends means that you are creating a subclass of the base class you are extending. You can only extend one class in your child class, but you can implement as many interfaces as you would like.

Sterling Egorichev

Reviewer

What is difference between class and interface?

A class describes the attributes and behaviors of an object. An interface contains behaviors that a class implements. A class may contain abstract methods, concrete methods. An interface contains only abstract methods.

Orbelinda Lecina

Reviewer

Can an interface extend a class?

Java interfaces cannot extend classes, which makes sense since classes contain implementation details that cannot be specified within an interface.. If you want to share code among all Vehicle instances, then you can use a (possibly abstract) class as a parent for any classes that need to implement that interface.

Jazmin Doll

Reviewer

What is string in Java?

String is a sequence of characters, for e.g. “Hello” is a string of 5 characters. In java, string is an immutable object which means it is constant and can cannot be changed once it has been created.

Charef Fadeev

Reviewer

What is super keyword in Java?

super is a keyword. It is used inside a sub-class method definition to call a method defined in the super class. Private methods of the super-class cannot be called. Only public and protected methods can be called by the super keyword. It is also used by class constructors to invoke constructors of its parent class.