Ruby object prints out as pointer

When you use new method, you get 'reference' on newly created object. puts kernel method returns some internal ruby information about this object. If you want to get any information about state your object, you can use getter method:

class Adder  def initialize(my_num)    @my_num = my_num  end  def my_num    @my_num  endendy = Adder.new(12)puts y.my_num  # => 12

Or you can use 'attr_reader' method that define a couple of setter and getter methods behind the scene:

class Adder  attr_accessor :my_num  def initialize(my_num)    @my_num = my_num  end      endy = Adder.new(12)puts y.my_num  # => 12

You aren't doing anything wrong. Assuming you see something like #<Adder:0xb7f9f710 @my_num=12> then in Ruby this is just the default representation of the object that you've created.

If you want to change this behaviour to be more friendly when you pass your object to puts you can override the to_s (to string) method. e.g.

class Adder  def initialize(my_num)    @my_num = my_num  end  def to_s    "Adder with my_num = #{@my_num}"  endend

then when you do puts y you'll see Adder with my_num = 12

You can also override the inspect method which is what is used, for example, when the Ruby irb console prints the representation of your object e.g.

class Adder  def inspect    to_s # return same representation as to_s  endend

then in irb:

>> y = Adder.new 12=> Adder with my_num = 12

That's because the object is a pointer. In Ruby, all objects are allocated on the heap, and the variables are just references to them.

When you do

puts y

It is actually calling the default to_s method of the object, which is just to output the class name, the memory location, and some info on the instance variables of the object.