Packages are used to organize classes into groups under a single namespace. Classes from other packages can be accessed using their fully qualified names or by importing the package. The import statement allows using a class without specifying the package, while package statements declare which package a class belongs to. Packages help avoid naming collisions and provide a way to encapsulate related classes together in a library.

1. PackagesDhrubojyotiKayal

2. PackagesImportAgenda

3. Contains a group of classes, organized together under a single namespace. Ex – java.util, java.sqlEssentially folder to store source and compiled classes – library / compilation unitHow can you use Classes in other packages?Using fully qualified class namepublic class FullQualification { public static void main(String[] args) { java.util.ArrayListlist = new java.util.ArrayList(); } } Package

4. Use import keyword to use one class in a different packageimport java.util.ArrayList; public class SingleImport { public static void main(String[] args) { ArrayListlist = new java.util.ArrayList(); } } If you want all the classes in java.util then Import java.util.*;Import

5. Use a package statement, it must appear as the first non-comment in the file.package com.training.javaYou creating a new compilation unit or libraryIn order to use the classes in this package you either use fully qualified class name or import statements Custom package

6. package com.training.java; public class MyClass { // ... } public class QualifiedMyClass { public static void main(String[] args) { com.training.java.MyClassm = new com.training.java.MyClass(); } } import com.training.java.MyClass; public class ImportedMyClass { public static void main(String[] args) { MyClassm = new MyClass(); } } Import in Action

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