demo assignment methods

README.md

WARNING Setter methods don’t return what you might think. When you use the syntactic sugar that lets you make calls to = methods look like assignments, Ruby takes the assignment semantics seriously. Assignments (like x=1) evaluate to whatever’s on their right-hand side. Methods usually return the value of the last expression evaluated during execution. But = method calls behave like assignments: the value of the expression ticket.price = 63.00 is 63.00, even if the ticket= method returns the string “Ha ha!” The idea is to keep the semantics consistent. Under the hood, it’s a method call; but it looks like an assignment and behaves like an assignment with respect to its value as an expression.

demo.out

a
fine
mess
a
fine
mess
#<RubyAssignmentDemo:0x007f9e82936e08 @a_field=[["a", "fine", "mess"]]>
[["a", "fine", "mess"]]

demo.rb

class RubyAssignmentDemo 
  
  attr_accessor :a_field

  def to_s
    @a_field.to_s
  end

  def a_field=(*args)
    @a_field = args
    "HA HA"
  end


end

demo = RubyAssignmentDemo.new

puts demo.a_field = %w{a fine mess}
puts demo.a_field
puts demo.inspect
puts demo.to_s