On Tue, Nov 24, 2009 at 12:00 PM, Chris P. [email protected]
wrote:
Basically I have 5 names entered into an array. They have a firstname
and surname. A middlename is then optional.
What I want to do is to print out the names like this…
John Seymour Smith
Peter Jones
Mary Walsh
So it yields the middlename and prints it out if it has one.
For starters, your Person class doesn’t need to mix-in Enumerable, and
it doesn’t need an “each” method. The array (people) that you’re
adding Person instances to is the thing that is enumerable, and it has
its own each method built-in. So a trimmed down Person class could
look like so:
class Person
include Comparable
attr_accessor :firstname, :middlename, :surname
def initialize (firstname, middlename, surname)
@firstname = firstname
@middlename = middlename
@surname = surname
end
def to_s
"Hello my name is #@firstname #@surname and i'm #@age"
end
def <=> (other)
(self.firstname) <=> (other.firstname)
end
end
Your comparison method (the <=> method) isn’t quite right, since it’s
only comparing their first names, but I’ll let you ponder how you
might improve that. You’re on the right track.
Now, given your requirement for how you’d like the names to be
printed, I think I’d also add a full_name() method to the Person
class, something like:
class Person
def full_name
unless middlename.empty?
"#{firstname} #{middlename} #{surname}"
else
"#{firstname} #{surname}"
end
end
end
Finally, there are several issues with the bit at the end where you’re
trying to iterate over the array of people. You have two loops (an
#each loop and then an #each_with_index loop) nested inside each
other. For the inner loop, the “index” and “person” arguments that
each_with_index() passes into the block aren’t instance variables, so
you just refer to them as “index” and “person”, not “@index” and
“@person”. I’d change that last bit to look like this:
people_sorted = people.sort
people_sorted.each_with_index do |person, index|
puts "Hi there #{index} #{person.full_name}!"
end
Hope this helps,
Lyle
