The comparator methods (<,>, etc.) can be useful for a lot of things. In
Ruby, they can be used to compare classes in order to understand how they
relate to one another on the class hierarchy.
# Fixnum is a subclass of Integer
> Fixnum < Integer
=> true
# Integer is not a subclass of Fixnum
> Integer < Fixnum
=> false
# Fixnum and String are not related to one another
> Fixnum < String
=> nil
The < operator will tell you if there is a subclass relationship. The >
operator will tell you if there is an ancestor relationship. When nil
results, it means the two classes do not have a direct relationship.
There are a few more of these types of operators on the Module class.