Programming Ruby 3.3

Defining Modules

module name     body end

A module is a collection of behaviors that are grouped together. The grouping can be used to include all the behaviors in a different module or class as one unit, or it can be used for name spacing. Like a class, the module body is executed during definition, and the resulting Module object is stored in a constant. A module may contain both class and instance methods and may define constants and class variables. (A module can also reference instance variables, but those are dependent on the module being added to a class; see the next section.)

As with classes, a module’s own methods (called module methods) are invoked using the Module object as a receiver, and constants are accessed using the :: scope ...