Question

The question is as of the title. Say I have a simple example below:

class Vehicle
  attr_accessor :wheels
end

class Car < Vehicle
  def initialize
    self.wheels = 4
  end
end

class Truck < Vehicle
  def initialize
    @wheels = 16
  end
end

I am curious which way is considered correct or better to invoke
wheels writer method of mother Vehicle?

Answer 1

self.wheels = 4 is more flexible because under the hood it is calling a setter method: self.wheels=(4)

So if you ever wanted to do something with the value before it is placed into @wheels, you could define that function:

def wheels=(val)
  # do something
  @wheels = new_val
end