What is The Difference Between a Public And a Non-Public Class

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A public class may be accessed outside of its package.

A non-public class may not be accessed outside of its package.

In Java, the access modifiers public, protected, package-private (default), and private are used to control the visibility and accessibility of classes, methods, and fields.

When it comes to classes specifically, there are two main categories: public classes and non-public classes (also known as package-private or default access).

  1. Public Class:
    • A class declared with the public modifier is accessible from any other class.
    • It can be used by classes in the same package, by classes in other packages, and by classes that are part of different projects.
    java
    public class PublicClass {
    // Class members and methods
    }
  2. Non-Public Class (Package-Private):
    • If no access modifier (default access) is specified for a class, it is considered to have package-private or default access.
    • A class with default access is accessible only within the same package. It is not visible to classes in other packages.
    java
    class PackagePrivateClass {
    // Class members and methods
    }

So, to answer the question “What is the difference between a public and a non-public class in Core Java?”:

  • Public Class: Accessible from any class, regardless of its package.
  • Non-Public Class (Package-Private): Accessible only within the same package.

Understanding these access modifiers is crucial for designing Java classes and managing the visibility of your code components.