In C++, the three access specifiers (public, protected, and private) control the visibility and accessibility of class members. Here are the differences between them:
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Public Access Specifier:
- Members declared as public are accessible from anywhere in the program.
- They can be accessed by objects of the class, as well as by any external functions or objects.
- Public members can also be inherited by derived classes and retain their public access in the derived class.
- Public access allows for wide accessibility and is typically used for interface definitions or members that need to be accessed externally.
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Protected Access Specifier:
- Members declared as protected have similar accessibility as private members but with additional access granted to derived classes.
- Protected members are accessible within the class itself and by derived classes.
- They are not accessible by objects of the class or any external functions or objects that are not derived classes.
- Protected access is useful when you want to provide access to derived classes while still restricting access to the general program.
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Private Access Specifier:
- Members declared as private are only accessible within the class itself.
- They cannot be accessed or modified directly by objects of the class or any external functions or objects.
- Private members are primarily used for encapsulation, hiding implementation details, and enforcing data integrity.
- Private members are not inherited by derived classes.
The access specifiers provide different levels of encapsulation and control over the visibility and accessibility of class members. They allow you to define which parts of a class should be visible to other parts of the program, ensuring proper encapsulation and data hiding. By carefully selecting the appropriate access specifier, you can design classes that enforce proper usage and maintain the integrity of the data.
