What is the difference between public, private, and protected access modifiers?

In object-oriented programming, access modifiers are used to control the visibility and accessibility of class members (variables, methods, and constructors) within a class hierarchy. The three main access modifiers are public, private, and protected. Here is a detailed explanation of each:

1. Public:
- Public access modifier allows unrestricted access to a class member from anywhere, both within and outside the class hierarchy.
- Public members can be accessed by any class or object, regardless of their location.
- They are often used for methods or variables that need to be accessed and modified by other classes or objects.

2. Private:
- Private access modifier restricts the access to a class member only within the same class where it is declared.
- Private members cannot be accessed or modified by any other class or object, even within the same package or subclass.
- They are typically used to encapsulate and hide implementation details, ensuring data integrity and preventing unauthorized access.

3. Protected:
- Protected access modifier allows access to a class member within the same class, subclasses, and other classes within the same package.
- Protected members are not accessible outside the package unless they are inherited by a subclass.
- They are commonly used when you want to provide access to derived classes while still restricting access to other classes or objects.

To summarize, the main differences between public, private, and protected access modifiers are:

- Public members have the widest accessibility, allowing access from anywhere.
- Private members have the narrowest accessibility, restricting access to only the declaring class.
- Protected members provide access within the same class, subclasses, and other classes within the same package.

These access modifiers play a crucial role in encapsulation, data hiding, and maintaining the integrity of object-oriented programming principles. They help in controlling the visibility and accessibility of class members, ensuring proper encapsulation and preventing unauthorized access to sensitive data.