In Ruby, if we define "c=(foo)" and it returns foo + 1, why is this not assigned to d = (self.c = 3)?

Question

the code is

def c=(foo)
  p "hello"
  return foo + 1
end

p self.c = 3
d = (self.c = 3)
p d

and it will print out 3 only... in other words, the returned value 4 is not assigned to d, why?

Answer 1

Setters return their argument (or right operand, depending on how you look at it) — always.