What is the most efficient way to initialize a Class in Ruby with different parameters and default values?

Question

I would like to have a class and some attributes which you can either set during initialization or use its default value.

class Fruit
  attr_accessor :color,         


        

Answer 1

Since Ruby 2.0 there is support of named or keyword parameters.

You may use:

class Fruit
  attr_reader      :color, :type

  def initialize(color: 'green', type: 'pear')
    @color = color
    @type = type
  end

  def to_s
    "#{color} #{type}"
  end
end

puts(Fruit.new)                                    # prints: green pear
puts(Fruit.new(:color => 'red', :type => 'grape')) # prints: red grape
puts(Fruit.new(:type => 'pomegranate')) # prints: green pomegranate

Some interesting notes on this topic:

• Keyword arguments in Ruby 2.0
• Ruby 2.0.0 by Example
• Named parameters in Ruby 2