From: JSU <juslander@...>
Date: 2009-06-17T07:00:05+09:00
Subject: Syntax error in Ruby Cookbook example

I am practicing/learning Ruby using Study Notes from www.ruby-lang.org.
I am working on Validation program taken from Ruby Cookbook, but
unable to run program as is.  Please advise where I may have gone
wrong.
Thanks in advance.  JSU




# p050inputvalidation.rb
# Here's an example from the Ruby Cookbook,
# showing how one can do validation of user's inputs.
class Name
   # Define default getter methods, but not setter methods.
   attr_reader :first, :last
   # When someone tries to set a first name,
   # enforce rules about it.
   def first=(first)
     if (first == nil or first.size == 0)
       raise ArgumentError.new('Everyone must have a first name.')
     end
     first = first.dup
     first[0] = first[0].chr.capitalize
     @first = first
end

# When someone tries to set a last name,
     # enforce rules about it.
  def last=(last)
     if  (last == nil || last.size == 0)
       raise ArgumentError.new('Everyone must have a last name.')
     end
     last[0] = last[0].chr.capitalize
     @last = last
  end

def full_name
     "#{@first} #{@last}"
  end
 # Delegate to the setter methods instead of
     # setting the instance variables directly.
  def initialize(first, last)
     self.first = first
     self.last = last
  end
end

jacob = Name.new('Jacob', 'Berendes')
jacob.first = 'Mary Sue'
jacob.full_name  # => "Mary Sue Berendes"
john = Name.new('John', 'Von Neumann')
john.full_name  # "John Von Neumann"
john.first = 'john'
john.first # =>  "john"
john.first = nil
# ArgumentError:  Everyone must have a first name.
Name.new('Kero, international football star and performance artist',
nil)
# ArgumentError:  Everyone must have a last name.

And my output is as follows:

>ruby p050inputvalidation.rb
p050inputvalidation.rb:11:in `first=': Everyone must have a first
name. (ArgumentError)
	from p050inputvalidation.rb:46
>Exit code: 1


Thanks again!