Module

< Object 78 instance methods 5 class methods

A Module is a collection of methods and constants. The methods in a module may be instance methods or module methods. Instance methods appear as methods in a class when the module is included, module methods do not. Conversely, module methods may be called without creating an encapsulating object, while instance methods may not. (See Module#module_function.)

In the descriptions that follow, the parameter sym refers to a symbol, which is either a quoted string or a Symbol (such as :name).

Example

module Mod
  include Math
  CONST = 1
  def meth
    #  ...
  end
end
Mod.class              #=> Module
Mod.constants          #=> [:CONST, :PI, :E]
Mod.instance_methods   #=> [:meth]

Class methods 5

.constants .nesting .new .used_modules .used_refinements

Instance methods 78

#< #<= #<=> #== #=== #> #>= #alias_method #ancestors #append_features #attr #attr_accessor #attr_reader #attr_writer #autoload #autoload? #class_eval #class_exec #class_variable_defined? #class_variable_get #class_variables #class_variable_set #const_added #constants #const_defined? #const_get #const_missing #const_set #const_source_location #define_method #deprecate_constant #extended #extend_object #freeze #include #include? #included #included_modules #inspect #instance_method #instance_methods #method_added #method_defined? #method_removed #method_undefined #module_eval #module_exec #module_function #name #prepend #prepended #prepend_features #private #private_class_method #private_constant #private_instance_methods #private_method_defined? #protected #protected_instance_methods #protected_method_defined? #public #public_class_method #public_constant #public_instance_method #public_instance_methods #public_method_defined? #refine #refinements #remove_class_variable #remove_const #remove_method #ruby2_keywords #set_temporary_name #singleton_class? #to_s #undefined_instance_methods #undef_method #using

Ruby version changes 12

3.3
- Module#set_temporary_name added for setting a temporary name for a module. [Feature #19521]
3.2
- Module.used_refinements has been added. [Feature #14332]
- Module#refinements has been added. [Feature #12737]
- Module#const_added has been added. [Feature #17881]
- Module#undefined_instance_methods has been added. [Feature #12655]
3.1
- Module#prepend now modifies the ancestor chain if the receiver already includes the argument. Module#prepend still does not modify the ancestor chain if the receiver has already prepended the argument. [Bug #17423]
- Module#private, public, protected, and module_function will now return their arguments. If a single argument is given, it is returned. If no arguments are given, nil is returned. If multiple arguments are given, they are returned as an array. [Feature #12495]
- New class which represents a module created by Module#refine. include and prepend are deprecated, and import_methods is added instead. [Bug #17429]
3.0
- Module#include and Module#prepend now affect classes and modules that have already included or prepended the receiver, mirroring the behavior if the arguments were included in the receiver before the other modules and classes included or prepended the receiver. [Feature #9573]
  
  Example
```
class C; end
module M1; end
module M2; end
C.include M1
M1.include M2
p C.ancestors #=> [C, M1, M2, Object, Kernel, BasicObject]
```
- Module#public, Module#protected, Module#private, Module#public_class_method, Module#private_class_method, toplevel “private” and “public” methods now accept single array argument with a list of method names. [Feature #17314]
- Module#attr_accessor, Module#attr_reader, Module#attr_writer and Module#attr methods now return an array of defined method names as symbols. [Feature #17314]
- Module#alias_method now returns the defined alias as a symbol. [Feature #17314]