Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Ruby Build an Address Book in Ruby Class Design Contact Class: Part 1

kabir k
PLUS
kabir k
Courses Plus Student 18,036 Points
Posted by kabir k
kabir k
Courses Plus Student 18,036 Points

Questions about the Contact class

I have some questions about the Contact class we just created in Contact Class: Part 1

class Contact
  attr_writer :first_name, :middle_name, :last_name

  def first_name
    @first_name
  end

  def middle_name
    @middle_name
  end

  def last_name
    @last_name
  end

  def full_name
    full_name = first_name
    if !@middle_name.nil?
      full_name += " "
      full_name += middle_name
    end
    full_name += ' '
    full_name += last_name
    full_name
  end
end

jason = Contact.new
jason.first_name = "Jason"
jason.last_name = "Seifer"
puts jason.full_name

nick = Contact.new
nick.first_name = "Nick"
nick.middle_name = "A"
nick.last_name = "Pettit"
puts nick.full_name

  1. Why are we not using the initialize method?

  2. Why do we need methods for the instance variables, @first_name, @middle_name, and @last_name when we've already made them attribute writers?

  3. And in the full_name method, why are we implicitly returning the full_name variable, and not explicitly returning it? Also, when should we implicitly return a value from a method? (as opposed to explicitly returning a value from the method)

2 Answers

Rafael Flores
PLUS
Rafael Flores
Courses Plus Student 22,056 Points
Rafael Flores
Rafael Flores
Courses Plus Student 22,056 Points
  1. The attr_writer method is a way to initialize. 2 and 3 have the same answer here in this exercise you are just learning different ways to do things. Do not get too hung up on those. In programming there is always many path to achieve the same. This is one way to get it done.

MOD NOTE: Moved from "Comment" to "Answer" (so it may be up-voted and/or marked as "Best Answer")

mkmk
mkmk
15,897 Points
mkmk
mkmk
15,897 Points

Also, re: #3 -- Ruby will implicitly return the last line of a function block, so you do not need to write the word 'return'. You can write 'return' if you would like, it's just not necessary.

Bear in mind that explicitly returning in Ruby is more memory intensive and could result in a noticeable performance hit if you are explicitly returning on every function.

rowend rowend
rowend rowend
2,926 Points
rowend rowend
rowend rowend
2,926 Points

mkmk there is a place to read about the fact of memory with return?