Classes and attr_reader in Ruby

A minimal class: initialize, instance variables and readers.

class Card
  attr_reader :rank, :suit

  def initialize(rank, suit)
    @rank = rank
    @suit = suit
  end

  def to_s
    "#{rank} of #{suit}"
  end
end

card = Card.new("ace", "spades")
puts card
puts card.rank

How it works

1. attr_reader writes the getter methods so you do not.
2. initialize runs on new and stores state in @ variables.
3. Defining to_s lets puts print the object sensibly.

Keywords and builtins used here

• Card
• class
• def
• end
• initialize
• puts
• to_s

The run, in numbers

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Step 1 of 3 in Classes & modules, step 19 of 29 in Language basics.

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