From: sempsteen <sempsteen@...>
Date: 2006-11-26T18:01:54+09:00
Subject: Re: coding practise

Yep, now i know that my Hash example is a different matter.

> The fix:
> change 'has_answer' to store the answer (privately) after calculating it and
> 'answer' to simply retrieve that answer if it has been created.

Where do you suggest to store the value for my amicable numbers example?

class Fixnum
  def has_friend?
    t1, t2 = 1, 1
    2.upto(self / 2) {|i| t1 += i if self % i == 0}
    2.upto(t1 / 2) {|i| t2 += i if t1 % i == 0}
    return self == t2 && self != t1
  end
  def friend
    t1, t2 = 1, 1
    2.upto(self / 2) {|i| t1 += i if self % i == 0}
    2.upto(t1 / 2) {|i| t2 += i if t1 % i == 0}
    return t1 if self == t2 && self != t1
  end
end

1.upto(1000) {|i| print i, "\t<->\t", i.friend, "\n" if i.has_friend?}

I want a "has_friend?" method and "friend" method. One for searching
for the existing of given number, other one is for getting the value
of the friend of that number. And i want those methods inside "Fixnum"
class structure, like as instance methods.
when i call has_friend? method it will store its value to some kind of
variable, but return true or false and, when i call friend method it
will get the stored value.
But what must be that some kind of variable that holds the value?
- class variable
- instance variable
- global
- or what?