Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Javascript > Javascript test %4

Reply
Thread Tools

Javascript test %4

 
 
Cogito
Guest
Posts: n/a
 
      03-07-2007
I'm trying to understand some Javascript code from a certain site.
Could you please tell me what does this test mean?
if ( j%4 == 0 )
What does %4 test for and is there a web site that explains it and,
presumably, also %1, %2 etc.
 
Reply With Quote
 
 
 
 
toff@arcticcoconut.com
Guest
Posts: n/a
 
      03-07-2007
That's the modulo operator:
http://www.webdevelopersnotes.com/tu...operators.php3

 
Reply With Quote
 
 
 
 
Randy Webb
Guest
Posts: n/a
 
      03-07-2007
Cogito said the following on 3/6/2007 11:52 PM:
> I'm trying to understand some Javascript code from a certain site.
> Could you please tell me what does this test mean?
> if ( j%4 == 0 )
> What does %4 test for and is there a web site that explains it and,
> presumably, also %1, %2 etc.


The statement above means if the remainder of dividing j by 4 is 0.
You can change the 0 to anything smaller than j.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/
 
Reply With Quote
 
Cogito
Guest
Posts: n/a
 
      03-07-2007
Such quick replies. It's simply magic.
Thank you guys.
 
Reply With Quote
 
Evertjan.
Guest
Posts: n/a
 
      03-07-2007
Randy Webb wrote on 07 mrt 2007 in comp.lang.javascript:

> Cogito said the following on 3/6/2007 11:52 PM:
>> I'm trying to understand some Javascript code from a certain site.
>> Could you please tell me what does this test mean?
>> if ( j%4 == 0 )
>> What does %4 test for and is there a web site that explains it and,
>> presumably, also %1, %2 etc.

>
> The statement above means if the remainder of dividing j by 4 is 0.
> You can change the 0 to anything smaller than j.
>


There is no such limitation.



But to be useful:
Anything? Also any fraction or any negative integer?

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)
 
Reply With Quote
 
Dr J R Stockton
Guest
Posts: n/a
 
      03-07-2007
In comp.lang.javascript message <Xns98EC70FE9A9DBeejj99@194.109.133.242>
, Wed, 7 Mar 2007 10:06:28, Evertjan. <(E-Mail Removed)>
posted:
>Randy Webb wrote on 07 mrt 2007 in comp.lang.javascript:
>
>> Cogito said the following on 3/6/2007 11:52 PM:
>>> I'm trying to understand some Javascript code from a certain site.
>>> Could you please tell me what does this test mean?
>>> if ( j%4 == 0 )
>>> What does %4 test for and is there a web site that explains it and,
>>> presumably, also %1, %2 etc.

>>
>> The statement above means if the remainder of dividing j by 4 is 0.
>> You can change the 0 to anything smaller than j.
>>

>
>There is no such limitation.
>
>
>
>But to be useful:
>Anything? Also any fraction or any negative integer?


Yes, yes.

ISTM that, unless the code is an obfuscation of false, the right hand
side must be, or have a chance of being, smaller in absolute value than
the divisor is or may be. And, generally, all three values need to be
such as can be represented exactly by an IEEE Double, including NaN, if
the statement is to be reliably usable.

The OP could easily have answered his question by searching the PDF of
the Standards (FAQ cites one of them, IIRC) for "%".

The sections of the standards dealing with the % operator need
rewriting; at present, they use "floating-point" to mean "non-integer".
All Numbers are floating point currently.

It's a good idea to read the newsgroup and its FAQ. See below.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6
news:comp.lang.javascript FAQ <URL:http://www.jibbering.com/faq/index.html>.
<URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.
 
Reply With Quote
 
Randy Webb
Guest
Posts: n/a
 
      03-07-2007
Evertjan. said the following on 3/7/2007 5:06 AM:
> Randy Webb wrote on 07 mrt 2007 in comp.lang.javascript:
>
>> Cogito said the following on 3/6/2007 11:52 PM:
>>> I'm trying to understand some Javascript code from a certain site.
>>> Could you please tell me what does this test mean?
>>> if ( j%4 == 0 )
>>> What does %4 test for and is there a web site that explains it and,
>>> presumably, also %1, %2 etc.

>> The statement above means if the remainder of dividing j by 4 is 0.
>> You can change the 0 to anything smaller than j.
>>

>
> There is no such limitation.
>
>


Tis true, but the results are pretty useles if k is smaller than j in j%k.

> But to be useful:
> Anything? Also any fraction or any negative integer?


Yes. Or at least testing doesn't throw up on fractions or negative
integers.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/
 
Reply With Quote
 
Dr J R Stockton
Guest
Posts: n/a
 
      03-07-2007
In comp.lang.javascript message <(E-Mail Removed)>,
Wed, 7 Mar 2007 08:51:12, Randy Webb <(E-Mail Removed)> posted:
>Evertjan. said the following on 3/7/2007 5:06 AM:
>> Randy Webb wrote on 07 mrt 2007 in comp.lang.javascript:
>>
>>> Cogito said the following on 3/6/2007 11:52 PM:
>>>> I'm trying to understand some Javascript code from a certain site.
>>>> Could you please tell me what does this test mean?
>>>> if ( j%4 == 0 )
>>>> What does %4 test for and is there a web site that explains it and,
>>>> presumably, also %1, %2 etc.
>>> The statement above means if the remainder of dividing j by 4 is 0.
>>> You can change the 0 to anything smaller than j.
>>>

>> There is no such limitation.
>>

>
>Tis true, but the results are pretty useles if k is smaller than j in j%k.


That is certainly not true, and neither is the converse. But if j is
*always* smaller than k, the operation is pointless.

>> But to be useful: Anything? Also any fraction or any negative
>>integer?

>
>Yes. Or at least testing doesn't throw up on fractions or negative
>integers.


Testing has its uses; but the standards are sufficiently clear. For
example, -6.875%1.25 has a meaning, and the operation gives it.

--
(c) John Stockton, Surrey, UK. ???@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
In MS OE, choose Tools, Options, Send; select Plain Text for News and E-mail.
Don't quote more than is needed, and respond after each quoted part.
 
Reply With Quote
 
Randy Webb
Guest
Posts: n/a
 
      03-08-2007
Dr J R Stockton said the following on 3/7/2007 11:48 AM:
> In comp.lang.javascript message <(E-Mail Removed)>,
> Wed, 7 Mar 2007 08:51:12, Randy Webb <(E-Mail Removed)> posted:
>> Evertjan. said the following on 3/7/2007 5:06 AM:
>>> Randy Webb wrote on 07 mrt 2007 in comp.lang.javascript:


<snip>

>>> But to be useful: Anything? Also any fraction or any negative
>>> integer?

>> Yes. Or at least testing doesn't throw up on fractions or negative
>> integers.

>
> Testing has its uses; but the standards are sufficiently clear. For
> example, -6.875%1.25 has a meaning, and the operation gives it.


Yeah, the "standards" are sufficiently useless also. We all know how
abundantly clear the "standards" are with regards to toFixed() now don't we?

Keep the "standards", give me testing.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
test test test richard Computer Support 3 01-24-2007 05:18 AM
TEST TEST Test...Blah Blah Blah generalbatguano@pacbell.net Computer Support 2 09-15-2006 03:47 AM
TEST TEST Test...Blah Blah Blah Generalbatguano@pacbell.net Computer Support 6 09-13-2006 01:53 AM
TEST TEST TEST Gazwad Computer Support 2 09-05-2003 07:32 PM
test test test test test test test Computer Support 2 07-02-2003 06:02 PM



Advertisments