What is #self The object itself. Inside the method, the instance to which the method belongs can be referenced by a pseudo variable named self. This in other languages. Characteristics of #self When a method call that omits the receiver is made in the method, self becomes the receiver. When the receiver can be omitted, it is often omitted.
How to use
class Numbers attr_accessor :number def set_number self.number = 30 # put 30 when calling this class number end end num1 = Numbers.new num1.set_number num1.number # => 30