how does Array#map have parameter to do something like this?

Question

def double(a)
 a*2
end

method_object = method(:double)

and here\'s my question, how does this code:

[1,3,5,6].map(&method_obje         


        

Answer 1

you can extend class integer:

class Integer
  def double
    self*2
  end
end

[1,2,3,4].map(&:double)
[
    [0] 2,
    [1] 4,
    [2] 6,
    [3] 8
]