Package And Interface In Java Pdf

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Packages and Interfaces both acts as a container.

Another unique feature in Java is Packages.

Difference Between Packages and Interfaces in Java

Packages and Interfaces both acts as a container. The content in packages and interfaces can be used by the classes by importing and implementing it correspondingly. The basic difference between packages and interfaces is that a package contains a group of classes and interfaces whereas, an interface contains methods and fields.

Interfaces is a group of abstract methods and constant fields. Keyword Packages are created using "Package" keyword. Interface are created using "Interface" keyword. Access keyword Packages can be imported using "import" keyword. Interfaces can be implemented using "implement" keyword. Packages are collection or groups of the variety of classes and interfaces.

The classes in packages are related to each other in some scope or by inheritance. You can also create your package and use it for your program. The packages created or available in the directory can be used in the program by using an import statement.

The import statement can be written in two ways, or you can say that there are two ways to access any package. In above code, the class TestMypackage has imported the package Mypackage and used its displayMypackage method. Interface is a kind of a class, but, differs in a sense that the methods declared in the interface are abstract that means the methods are only declared but not defined.

The fields in the interface are always public, static, final. The fields must be initialized at the time of declaration. The methods declared by the interface are defined by the class which implements that interface according to its requirement. As the methods in the interface do not perform any function, so there is no use of creating any object of the interface.

Hence, no object can be created for the interface. The interface can also inherit the other interface but, the class inheriting such an interface must also implement all the methods of the inherited interface. In above code, we had created an interface Area, and the class Circle has implemented the interface Area. The class Circle has defined the abstract method of the class area according to its requirement.

Both packages and interface are the containers. Package reduces the size of the code as we just import the class to be used instead of again define it. Whereas the interface reduces the confusions occurred while multiple inheritances because in the case of multiple inheritances the inheriting class has not to decide that definition of which method it should inherit instead it defines its own.

May god bless you and give you the endurance to keep helping others. Thank you for the definition, completely cleared the doubts regarding interface and package. Thank you so much. Your email address will not be published. Key Differences Between Packages and Interfaces in Java A package is a group of classes and interfaces together whereas, an interface is a group of abstract methods.

Package is created using a keyword package whereas, an interface is created using a keyword interface. If a class or an interface inside a package is to be used the package is to be imported while an interface has to be implemented. Comments superb thank you so much for explaining the differences so well. Leave a Reply Cancel reply Your email address will not be published. An interface can be extended by another interface and implemented by the class.

Difference Between Packages and Interfaces in Java

Chapter Figure Synopsis Class Name: java. BitSet Superclass: java. Cloneable , java.

Package in Java is a mechanism to encapsulate a group of classes, sub packages and interfaces. Packages are used for:. All we need to do is put related classes into packages. After that, we can simply write an import class from existing packages and use it in our program. A package is a container of a group of related classes where some of the classes are accessible are exposed and others are kept for internal purpose. We can reuse existing classes from the packages as many time as we need it in our program.

For example, in Java, all the classes and interfaces which perform input and output operations are stored in package. ➢ Packages hide the classes and.

Packages & Interfaces in Java

Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available. To create a package, you choose a name for the package naming conventions are discussed in the next section and put a package statement with that name at the top of every source file that contains the types classes, interfaces, enumerations, and annotation types that you want to include in the package. The package statement for example, package graphics; must be the first line in the source file. There can be only one package statement in each source file, and it applies to all types in the file.

Difference Between Packages and Interfaces in Java

Java Interface

It helps organize your classes into a folder structure and make it easy to locate and use them. More importantly, it helps improve code reusability. Each package in Java has its unique name and organizes its classes and interfaces into a separate namespace, or name group. Although interfaces and classes with the same name cannot appear in the same package, they can appear in different packages. This is possible by assigning a separate namespace to each Java package. Syntax:- package nameOfPackage; The following video takes you through the steps of creating a package.

In this tutorial, we will learn about Java interfaces. We will learn how to implement interfaces and when to use them in detail with the help of examples. An interface is a fully abstract class. It includes a group of abstract methods methods without a body. To use an interface, other classes must implement it. We use the implements keyword to implement an interface.

A Package can be defined as a grouping of related types classes, interfaces, interfaces. Below given package example contains interface named animals.

Packages in Java: How to Create/Import Package

The main difference between package and interface is that a package is a collection of related classes and interfaces while an interface is a collection of fields and abstract methods. Package and interface are two main concepts in Object Oriented Programming based languages such as Java. A package has a set of associated classes and interfaces. An interface has a set of fields and abstract methods.

Interface in Java

The -d switch specifies the destination where to put the generated class file. If you want to keep the package within the same directory, you can use. How to run java package program You need to use fully qualified name e.