Programming Ruby 3.3

Access Control

private <symbol>^* protected <symbol>^* public <symbol>^*

Ruby defines three levels of access protection for module and class constants and methods:

• Public—Accessible to anyone.
• Protected—Can be invoked only by objects of the defining class and its subclasses.
• Private—Can be called only with self as the receiver, including both implicit and explicit uses of self. Private methods therefore can be called in the defining class and by that class’s descendants and ancestors, but only within the same object. (See ​Specifying Access Control​ for examples.)

These levels are invoked with the methods public, protected, and private, which are defined in class Module. Each access control function can be used in three different ways:

• If used ...