From: Ian Asaff <ian.asaff@...>
Date: 2012-02-09T03:33:47+09:00
Subject: Re: Require bug confirmation: possible 'times' method error

You never hit your return statement (num is never > 5), so the method just
returns the last thing it evaluated.

1.9.3-p0 :003 > 6.times {|n| puts n}
0
1
2
3
4
5
=> 6 #returns 6

Your method returns only 6.

Also, give people who help you over the internet the benefit of the doubt.
I don't think anyone was trying to waste your time :)




On 2/8/12 1:12 PM, "Tom Clarke" <tarclarke@gmail.com> wrote:

>Hi Randy,
>
>Thank you for your reply.
>
>I have already tried 7.times, which fixes the issue, but that is not
>relevant to the issue I raised.
>
>Let's remind ourselves of the most pertinent section of the code in
>question:
>return num, square if num > 5
>
>At the last time when this code is encountered, num is equal to 6 (as is
>displayed by the later 'puts num' statement output). The value for square
>is to be outputted if num is greater than 5. As 6 is greater than 5 then
>the value for square should be returned (which will be 36 when num is 6).
>
>So it doesn't matter whether it's fixed with 7.times, what matters is what
>happens when 6.times is used. What I'm trying to establish is whether
>there
>is a bug in the current Ruby implementation, and workarounds to edge cases
>like this will not help bugs to be fixed.
>
>So, with this in mind, why does a value for square not get returned when
>num = 6?
>
>Thanks in advance for your advice,
>Tom
>
>On 8 February 2012 17:43, Randy Coulman <rcoulman@gmail.com> wrote:
>
>> I think you're seeing expected behavior here.
>>
>> A Ruby method will return the value of the last expression in the
>>method,
>> unless there is an earlier return statement.
>>
>> In the interest of "teaching you to fish", I'll just ask a couple of
>> leading questions:
>>
>> What happens if you use 5.times?
>>
>> What happens if you use 7.times?
>>
>> Does that help?
>>
>> Randy
>>
>> On Wed, Feb 8, 2012 at 8:56 AM, Tom Clarke <tarclarke@gmail.com> wrote:
>>
>> > Hi all,
>> >
>> > First time posting here. I'm a Ruby newbie, so apologies if this
>>question
>> > sounds dumb.
>> >
>> > I've found something I'm unable to explain. It's either a 'bug' or a
>> > confusing feature. See code below (taken from rubylearning.com):
>> > ---
>> > "# p019mtdarry.rb
>> >
>> > # if you give return multiple parameters,
>> > # the method returns them in an array
>> > # The times method of the Integer class iterates block num times,
>> > # passing in values from zero to num-1
>> >
>> > def mtdarry
>> >  10.times do |num|
>> >  square = num * num
>> >  return num, square if num > 5
>> >  end
>> > end
>> >
>> >
>> > # using parallel assignment to collect the return value
>> > num, square = mtdarry
>> >
>> > puts num
>> > puts square"
>> > ---
>> > The output is meant to be as follows:
>> > ---
>> > ">ruby p019mtdarry.rb
>> > 6
>> > 36
>> > >Exit code: 0"
>> > ---
>> > This is the output for the code above. However, if I change 10.times
>>to
>> > 6.times, the 'puts num' output is 6, and the square output is blank.
>> >
>> > The reason this is odd is, if the values for num go from 0 to 5, then
>>the
>> > output of puts num should be 5. However, as the output of puts num is
>>6,
>> > then the puts square output should be 36, but instead it is blank.
>> >
>> > I've tested this on both Ruby 1.9.2 and 1.9.3 (p0). My question is,
>> should
>> > I raise this as a bug or have I missed something in my program
>>analysis?
>> >
>> > Thanks,
>> > Tom
>> >
>>
>>
>>
>> --
>> Randy Coulman
>> rcoulman@gmail.com
>> Twitter: @randycoulman
>>