In Ruby, an Eigenclass, also called a Singleton Class, is where methods defined on a specific object are actually stored. In the inheritance chain, it sits between an object and its class.
An Eigenclass, also known as a "Singleton Class," is an invisible class created by the Ruby interpreter when you define methods on a specific object. For example:
class American
def greet
puts "Nice to meet you!"
end
end
lucy = American.new
# This method actually gets defined on
# lucy's eigenclass
def lucy.greet
puts "Hi, I'm Lucy."
# "super" tries to call a method by
# the same name as this one, further
# up the inheritance chain. In this
# case, it will find American#greet
super
end
lucy.greet
# "Hi, I'm Lucy."
# "Nice to meet you!"
Further reading:
