Access instance variable using its name (as symbol)

Question

In Ruby, I have this class:

class Position
  attr_reader :x, :y
  def initialize(x, y)
      @x, @y = x, y
  end
end

What I want to do is to access x and y variables using the symbol, something like this:

axis = :x
pos = Position.new(5,6)
 #one way:
pos.axis # 5 (pos.x)
 #other way:
pos.get(axis) # 5 (pos.x)

Thanks to this question I've found with this code, I can achieve the second behavior.

#...
class Position
  def get(var)
    instance_variable_get(("@#{var}").intern)
  end
end

But it seems ugly and inefficient (especially converting symbol to string and back to symbol). Is there a better way?

Answer 1

Easy, use the send method

class Position
  attr_reader :x, :y

  def initialize(x, y)
    @x, @y = x, y
  end
end
 => nil 

pos = Position.new(5,5)
 => #<Position:0x0000010103d660 @x=5, @y=5> 

axis = :x
 => :x 

pos.send axis
 => 5