def ==(other)
(@value == other.value) && (@suit == other.suit)
end

Although maybe you’d like to leave == for object identity comparison….

As to the “to_str” method… well, you’d use “to_s” which is what puts calls.

Why? Well because puts is supposed to print objects of any type. to_str would only exist in objects which are ‘would-be-strings’.

It’s a bit confusing, but these links may help:

http://www.ruby-forum.com/topic/59379
“to_str …. is reserved for classes that are made to be used in place of
Strings, when they need to be converted to true Strings”

http://whytheluckystiff.net/articles/rubyOneEightOh.html
“With to_str, Matz is giving us a simpler way of demonstrating that our classes can be used as strings directly. Nearly all builtin methods use to_str to determine if an object is (or can be used as) a String. Think of it: if you extend the String class, then you have to write alternate methods (sub!, length, append, etc.) tailored to your needs.
…
So why not use to_s? Because to_s coerces objects into strings. So, to_str is an implicit cast, whereas to_s is an explicit cast.

Think of timestamps. We want to be able to easily convert a timestamp into a String for printing:

puts “Time.now: ” + Time.now.to_s
#=> Time.now: Mon Aug 04 13:37:43 MDT 2003

But we don’t want to load a File based on a timestamp:

File.open( Time.now )
#=> TypeError: cannot convert Time into String
from (irb):3:in `initialize’
from (irb):3:in `open’
from (irb):3

Generally, we just don’t need a timestamp to act as a String. So we use to_s to explicitly convert it.”