Integer Check

[Dennis M. Marks]

What is the best way to validate a field as a positive or negative
integer?

--
Dennis M. Marks

http://www.dcs-chico.com/~denmarks/

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[William Morris]

Re: Integer Check

myvar < 0
myvar > 0 ?


"Dennis M. Marks" <denmarks@domai n.invalid> wrote in message
news:2004200407 33235484%denmar ks@domain.inval id...[color=blue]
> What is the best way to validate a field as a positive or negative
> integer?
>
> --
> Dennis M. Marks
> http://www.dcs-chico.com/~denmarks/
> Replace domain.invalid with dcsi.net
>
>
> -----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
> http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
> -----== Over 100,000 Newsgroups - 19 Different Servers! =-----[/color]

[Vincent van Beveren]

Re: Integer Check

if (isNan(myVariab le)) {
alert('incorrec t, not a number');
} else {
if ((myVariable % 1)!=0) {
alert('Number can not be a floating-point');
} else return true;

return false;
}

[Dennis M. Marks]

Re: Integer Check

In article <40853795$0$558 $e4fe514c@news. xs4all.nl>, Vincent van
Beveren <vincent@provid ent.remove.this .nl> wrote:
[color=blue]
> if (isNan(myVariab le)) {
> alert('incorrec t, not a number');
> } else {
> if ((myVariable % 1)!=0) {
> alert('Number can not be a floating-point');
> } else return true;
>
> return false;
> }
>
>[/color]

Thank you (except it has to be isNaN)
I would never have thought of your way to check for integer.

--
Dennis M. Marks

http://www.dcs-chico.com/~denmarks/

Replace domain.invalid with dcsi.net


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[Mick White]

Re: Integer Check

Vincent van Beveren wrote:
[color=blue]
> if (isNan(myVariab le)) {
> alert('incorrec t, not a number');
> } else {
> if ((myVariable % 1)!=0) {
> alert('Number can not be a floating-point');
> } else return true;
>
> return false;
> }
>[/color]


Why not:
function isInteger(num){
return (!isNaN(num) && num%1==0);
}
?
Mick

[Evertjan.]

Re: Integer Check

Mick White wrote on 20 apr 2004 in comp.lang.javas cript:
[color=blue]
> Vincent van Beveren wrote:
>[color=green]
>> if (isNan(myVariab le)) {
>> alert('incorrec t, not a number');
>> } else {
>> if ((myVariable % 1)!=0) {
>> alert('Number can not be a floating-point');
>> } else return true;
>>
>> return false;
>> }
>>[/color]
>
>
> Why not:
> function isInteger(num){
> return (!isNaN(num) && num%1==0);
>}
> ?
> Mick
>[/color]

return !(isNaN(num) || !(num % 1));

or

return !isNaN(num) && !!(num % 1);


--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Dr John Stockton]

Re: Integer Check

JRS: In article <20042004073323 5484%denmarks@d omain.invalid>, seen in
news:comp.lang. javascript, Dennis M. Marks <denmarks@domai n.invalid>
posted at Tue, 20 Apr 2004 07:33:23 :
[color=blue]
>What is the best way to validate a field as a positive or negative
>integer?[/color]

How about a zero one? Do you want to allow a floating-point form of a
value which happens to be integer, such as 1e6 or 3.000 ? How about
0xFF ?

OK = /^[+-]?\d+$/.test(field)
tests for optional sign followed by only decimal digits. \d{1,6} might
be preferred, likewise [+- ] .

See <URL:http://www.merlyn.demo n.co.uk/js-valid.htm>.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang. javascript
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[Vincent van Beveren]

Re: Integer Check

>>Why not:[color=blue][color=green]
>>function isInteger(num){
>>return (!isNaN(num) && num%1==0);
>>}
>>?
>>Mick
>>[/color]
>
>
> return !(isNaN(num) || !(num % 1));
>
> or
>
> return !isNaN(num) && !!(num % 1);
>[/color]

I just wrote the code as a draft. Any of these are good.

return (!isNaN(num)) && ((num % 1)==0)

would probably be the most relayable... since num % 1 is a
calculation, it would be better to see if it matches a number,
even though 0 == false.

[Evertjan.]

Re: Integer Check

Vincent van Beveren wrote on 21 apr 2004 in comp.lang.javas cript:[color=blue][color=green]
>> return !(isNaN(num) || !(num % 1));
>>
>> or
>>
>> return !isNaN(num) && !!(num % 1);
>>[/color]
>
> I just wrote the code as a draft. Any of these are good.
>
> return (!isNaN(num)) && ((num % 1)==0)
>
> would probably be the most relayable... since num % 1 is a
> calculation, it would be better to see if it matches a number,
> even though 0 == false.[/color]

I do not know about this relaying,
but any nonzero number is considered true in javascriot.

var nonzeronumber = 2;
alert(!!nonzero number) // gives true

var zeronumber = 0;
alert(!!zeronum ber) // gives false

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Richard Cornford]

Re: Integer Check

Evertjan. wrote:[color=blue]
> Vincent van Beveren wrote on 21 apr 2004 in comp.lang.javas cript:[color=green][color=darkred]
>>> return !(isNaN(num) || !(num % 1));
>>>
>>> or
>>>
>>> return !isNaN(num) && !!(num % 1);
>>>[/color]
>>
>> I just wrote the code as a draft. Any of these are good.
>>
>> return (!isNaN(num)) && ((num % 1)==0)
>>
>> would probably be the most relayable... since num % 1 is a
>> calculation, it would be better to see if it matches a number,
>> even though 0 == false.[/color]
>
> I do not know about this relaying,
> but any nonzero number is considered true in javascriot.
>
> var nonzeronumber = 2;
> alert(!!nonzero number) // gives true
>
> var zeronumber = 0;
> alert(!!zeronum ber) // gives false[/color]

If there is a desire to explicitly return a boolean value, but avoid the
extra comparisons, it might be practical to apply the NOT operator to
the result of the whole expression:-

return !(isNaN(num)||( num % 1));

Richard.