From: Charles A Gray <smgspices@...>
Date: 2006-12-27T10:20:32+09:00
Subject: Peculiar Behavior for a Newby to Undertstand

I created a class for prime numbers as so:

class Primes
    def initialize
    end
    
    def prime?(number)
        # Method returns true if number is prime.
        limit = Math.sqrt(number).ceil
        flag = true
        if number % 2 == 0
            flag = false
        else
            3.step(limit,2) {|i| 
                if number % i == 0
                    flag = false
                    break
                end
            }
        end
        return flag
    end
    
    def show_primes(lower, upper)
        # Prints all primes between lower and upper
        # Lower is incremented 1 if it is even.
        # The arcane "(((lower/2).floor)*2+1)" performs this task
        (((lower/2).floor)*2+1).step(upper,2) {|i| 
            if prime?(i) == true
                print i.to_s + " "
            end
        }
    end
    end
Then when I enter
a=primes.new
a.show_primes(1000000,1000100) I get
1000003 1000033 1000037 1000039 1000081 1000099 1000001
Where is that trailing 1000001 coming from? It is not a prime number and
in fact is the lower limit.
If I enter the same methods outside of class Primes and enter
show_primes(1000000,1000100) I don't get the lower limit at the end of
the printed values.

I am running version 1.18.4 using scite in Ubuntu.
-- 
Charles Gray -- Phoenix, AZ; Where you can bake the chill out of your
bones