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comp.lang.ruby

fixnum problem plz help

Guy Dols

3/3/2009 9:29:00 PM

hy

i am new to ruby i am trieng to get some skils but i have a problem when
i use a fixnum :

years = ask("")
days = years * 365
puts days


my answer is
222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222

but i should be 730

i have an screenshot as an attachment plz help me
--
Posted via http://www.ruby-....
12 Answers

Michael Malone

3/3/2009 9:35:00 PM

0

Guy Dols wrote:
> hy
>
> i am new to ruby i am trieng to get some skils but i have a problem when
> i use a fixnum :
>
> years = ask("")
> days = years * 365
> puts days
>
>
> my answer is
> 222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>
> but i should be 730
>
> i have an screenshot as an attachment plz help me
>
Please paste your ask() Method. That appears to be where the problem is.

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pjb

3/3/2009 9:42:00 PM

0

Guy Dols <guy_dols@hotmail.com> writes:

> hy
>
> i am new to ruby i am trieng to get some skils but i have a problem when
> i use a fixnum :
>
> years = ask("")
> days = years * 365
> puts days
>
>
> my answer is
> 222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>
> but i should be 730


I think you are lying. Twice.

First, the answer is probably not what you're telling but rather:

22222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222

Then it should NOT be 730, but what you get.

This is because for all we know, ask("") is returning "2" and 365
times "2" is a string containing 365 2s. At least in such a inferior
language as Ruby.



In more strongly typed programming languages such as Common Lisp,
you'd get an error:

C/USER[929]> (* "2" 365)

*** - *: "2" is not a number



> i have an screenshot as an attachment plz help me

Good for you!


--
__Pascal Bourguignon__

Michael Malone

3/3/2009 9:49:00 PM

0

Pascal J. Bourguignon wrote:
> Guy Dols <guy_dols@hotmail.com> writes:
>
>
>> hy
>>
>> i am new to ruby i am trieng to get some skils but i have a problem when
>> i use a fixnum :
>>
>> years = ask("")
>> days = years * 365
>> puts days
>>
>>
>> my answer is
>> 222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>>
>> but i should be 730
>>
>
>
> I think you are lying. Twice.
>
> First, the answer is probably not what you're telling but rather:
>
> 22222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>
> Then it should NOT be 730, but what you get.
>
> This is because for all we know, ask("") is returning "2" and 365
> times "2" is a string containing 365 2s. At least in such a inferior
> language as Ruby.
>
>
Unsuccessful troll is unsuccessful.
>
> In more strongly typed programming languages such as Common Lisp,
> you'd get an error:
>
> C/USER[929]> (* "2" 365)
>
> *** - *: "2" is not a number
>
>
>
>
>> i have an screenshot as an attachment plz help me
>>
>
> Good for you!
>
>
>


=======================================================================
This email, including any attachments, is only for the intended
addressee. It is subject to copyright, is confidential and may be
the subject of legal or other privilege, none of which is waived or
lost by reason of this transmission.
If the receiver is not the intended addressee, please accept our
apologies, notify us by return, delete all copies and perform no
other act on the email.
Unfortunately, we cannot warrant that the email has not been
altered or corrupted during transmission.
=======================================================================

Ken Bloom

3/3/2009 11:02:00 PM

0

On Tue, 03 Mar 2009 16:28:48 -0500, Guy Dols wrote:

> hy
>
> i am new to ruby i am trieng to get some skils but i have a problem when
> i use a fixnum :
>
> years = ask("")
> days = years * 365
> puts days
>
>
> my answer is
>
222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>
> but i should be 730
>
> i have an screenshot as an attachment plz help me

Ask is returning the string "2" instead of the number 2.
When you use the multiplication operator on a string, it creates a longer
string with that many copies of the string concatenated back to back, so
instead of multiplying the number 2 by 365 to give 730, you got a string
containing exactly 365 twos.

years=ask("").to_i

--Ken

--
Chanoch (Ken) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu...

Tom Cloyd

3/4/2009 12:20:00 AM

0

Pascal J. Bourguignon wrote:
> Guy Dols <guy_dols@hotmail.com> writes:
>
>
>> hy
>>
>> i am new to ruby i am trieng to get some skils but i have a problem when
>> i use a fixnum :
>>
>> years = ask("")
>> days = years * 365
>> puts days
>>
>>
>> my answer is
>> 222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>>
>> but i should be 730
>>
>
>
> I think you are lying. Twice.
>
> First, the answer is probably not what you're telling but rather:
>
> 22222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222
>
> Then it should NOT be 730, but what you get.
>
> This is because for all we know, ask("") is returning "2" and 365
> times "2" is a string containing 365 2s. At least in such a inferior
> language as Ruby.
>
>
>
> In more strongly typed programming languages such as Common Lisp,
> you'd get an error:
>
> C/USER[929]> (* "2" 365)
>
> *** - *: "2" is not a number
>
>
>
>
>> i have an screenshot as an attachment plz help me
>>
>
> Good for you!
>
>
>
And for the benefits, such as they are, of strong typing, we get to a
whole other level of detail to attend to. No thanks. Did that for a time
with Pascal. I prefer the mindless grace of waterfowl.

t.

--

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tom Cloyd, MS MA, LMHC - Private practice Psychotherapist
Bellingham, Washington, U.S.A: (360) 920-1226
<< tc@tomcloyd.com >> (email)
<< TomCloyd.com >> (website)
<< sleightmind.wordpress.com >> (mental health weblog)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

William James

3/4/2009 8:02:00 AM

0

Pascal J. Bourguignon wrote:

> This is because for all we know, ask("") is returning "2" and 365
> times "2" is a string containing 365 2s. At least in such a inferior
> language as Ruby.
>
>
>
> In more strongly typed programming languages such as Common Lisp,

Typo. Should be Commune Lisp.

> you'd get an error:
>
> C/USER[929]> (* "2" 365)
>
> *** - *: "2" is not a number

Commune Lisp:
(* "2" 9)
*** ERROR!!! ***

Awk:
"2" * 9
18

Ruby:
"2" * 9
"222222222"

Now, which is the lowest-level language?

Brian Candler

3/4/2009 8:59:00 AM

0

Pascal J. Bourguignon wrote:
> In more strongly typed programming languages such as Common Lisp,
> you'd get an error:
>
> C/USER[929]> (* "2" 365)
>
> *** - *: "2" is not a number

This is nothing to do with "strongly typed". Ruby's concept of the
difference between a string and an integer is just as strict as LISP's.

Rather, Ruby provides semantics to the '*' operator/function for strings
which LISP doesn't.

You can get exactly the behaviour you desire by _removing_ some Ruby
functionality.

irb(main):001:0> String.class_eval { undef_method(:*) }
=> String
irb(main):002:0> "2" * 365
NoMethodError: undefined method `*' for "2":String
from (irb):2
from :0
--
Posted via http://www.ruby-....

pjb

3/4/2009 9:48:00 AM

0

Brian Candler <b.candler@pobox.com> writes:

> Pascal J. Bourguignon wrote:
>> In more strongly typed programming languages such as Common Lisp,
>> you'd get an error:
>>
>> C/USER[929]> (* "2" 365)
>>
>> *** - *: "2" is not a number
>
> This is nothing to do with "strongly typed". Ruby's concept of the
> difference between a string and an integer is just as strict as LISP's.
>
> Rather, Ruby provides semantics to the '*' operator/function for strings
> which LISP doesn't.
>
> You can get exactly the behaviour you desire by _removing_ some Ruby
> functionality.
>
> irb(main):001:0> String.class_eval { undef_method(:*) }
> => String
> irb(main):002:0> "2" * 365
> NoMethodError: undefined method `*' for "2":String
> from (irb):2
> from :0

Right, it is too much overloading, not weak typing. Sorry for the confusion.

--
__Pascal Bourguignon__

Thomas Preymesser

3/4/2009 1:05:00 PM

0

2009/3/4 William James <w_a_x_man@yahoo.com>:
> Pascal J. Bourguignon wrote:
>
>> This is because for all we know, ask("") is returning "2" and 365
>> times "2" is a string containing 365 2s. =A0At least in such a inferior
>> language as Ruby.
>>
>>
>>
>> In more strongly typed programming languages such as Common Lisp,
>
> Typo. =A0Should be Commune Lisp.
>
>> you'd get an error:
>>
>> C/USER[929]> (* "2" 365)
>>
>> *** - *: "2" is not a number
>
> Commune Lisp:
> =A0(* "2" 9)
> =A0*** ERROR!!! ***
>
> Awk:
> =A0"2" * 9
> =A018
>
> Ruby:
> =A0"2" * 9
> =A0"222222222"

C:
printf("%d\n",'2'*9);
450


--=20
Thomas Preymesser
thopre@gmail.com
http://thopre.google...
http://thopre.word...
Sent from: Berlin Berlin Deutschland.

Yossef Mendelssohn

3/4/2009 5:51:00 PM

0

On Mar 3, 3:49=A0pm, Michael Malone <michael.mal...@tait.co.nz> wrote:
> Unsuccessful troll is unsuccessful.

I had to re-read the post to be sure it actually came from Pascal.
After all, there were no nested parens in the entire thing.

--
-yossef