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!