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Re: bug in is_numeric [message #181339 is a reply to message #181338]

Sun, 12 May 2013 23:27

Thomas 'PointedEars'
Messages: 701
Registered: October 2010

Karma:

Senior Member

Jerry Stuckle wrote:

> On 5/12/2013 2:39 PM, Thomas 'PointedEars' Lahn wrote:
>> Jerry Stuckle wrote:
>>> On 5/12/2013 1:38 PM, Thomas 'PointedEars' Lahn wrote:
>>>> Thomas Mlynarczyk wrote:
>>>> > Sanders Kaufman schrieb:
>>>> >>> if(is_numeric('x11.11c') returns TRUE
>>>> >> Try it without the quotation marks around the number.
>>>> >
>>>> > Which number? x11.11c is not a number.
>>>>
>>>> The misconception might partially draw from the fact that 0x11 is a
>>>> number,
>>>> the hexadecimal representation of decimal 16¹ + 16⁰ = 17 (even in PHP).
>>>> In other programming languages that require a leading “0” and do not
>>>> have “.” as (concatenation) operator,
>>>>
>>>> x11.11c
>>>>
>>>> could be the representation of decimal 16¹ + 16⁰ + 16⁻¹ + 16⁻² + 13 ×
>>>> 16⁻³ = 17.06958 (BTW, I have written a drop-in replacement for
>>>> ECMAScript's parseFloat() that can do that, with the usual rounding
>>>> errors [1]).
>>>>
>>>> In PHP, however,
>>>>
>>>> x11.11c
>>>>
>>>> would be equivalent to
>>>>
>>>> (x11) . (11c)
>>>>
>>>
>>> Wrong, as usual.
>>>
>>> <snip>
>>
>> Intentionally misquoted, as usual.
>
> And exactly what is wrong with what I quoted?

In contrast to what you stated, exactly *nothing* is wrong with it when
properly quoted; that is, *in context*, which is the point. Giving you the
benefit of a doubt, you appear to have severe difficulty understanding the
concept of context as such and the importance of context in quotations
specifically; it would be good if you could work on that.

> The rest of your trash

Not everything that you choose to ignore or fail to understand is “trash”
because of that.

> was based on this incorrect premise; it would be a waste of bandwidth to
> repost your entire tripe.

As showed by the PHP output that I posted further below, and that you
snipped, the premise is _not_ incorrect. To elaborate:

“.” would be considered a concatenation operator here; there is no other
production of the PHP grammar that fits the source code better. Numeric
literals must not start with “x” in PHP, which precludes the possibility
that “.” would be parsed as a decimal point of the literal “x11.11” (which,
giving you the benefit of a doubt, might have been your assumption drawing
from other programming languages that you might know).

As a result, “x11“ would be considered a constant's identifier; because such
a constant would likele be undeclared, it would be parsed as if it was a
string value containing the characters of the would-be identifier as
characters (see the PHP Notices in the test, and the generated output for
proof of that).

“11c” would be considered a constant identifier as well (and treated the
same way) if it did not start with a decimal digit. Or it would be
considered a decimal literal if it did not contain/end with “c” (allowed
would only be “e” followed by a decimal literal, for the
exponential/scientific decimal format). But as it does contain/end with “c”
that is not in a hexadecimal literal, it is a *syntax error*. Therefore,
the entire expression would not compile and the entire PHP program would not
compile, being syntactically in error.

We have now ascertained that, as Thomas Mlynarczyk stated, “x11.11c” cannot
be a proper numeric literal in PHP (it would be an operation expression
[that would not compile, but that is unimportant from here]). As that is
the case, “'x11.11c'” also is not considered numeric in PHP, which is why

is_numeric('x11.11c')

must return FALSE. By contrast, is_numeric('0x11') returns TRUE.

However, there appears to be an *actual* mismatch between PHP manual and
implementation in said PHP version as

is_numeric('0b11001001')

returns FALSE when according to the manual it should return TRUE (binary
integer literals are available since PHP 5.4.0 per the manual, and they do
compile and properly evaluate in tests there.

> [more flames]

It is a pity that too often you are not able to master your emotions in
order to participate in a factual discussion in a constructive way.

PointedEars
--
Use any version of Microsoft Frontpage to create your site.
(This won't prevent people from viewing your source, but no one
will want to steal it.)
-- from <http://www.vortex-webdesign.com/help/hidesource.htm> (404-comp.)

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[Message index]

		bug in is_numeric By: fred on Sun, 12 May 2013 14:22
		Re: bug in is_numeric By: Salvatore on Sun, 12 May 2013 15:31
		Re: bug in is_numeric By: Luuk on Sun, 12 May 2013 15:55
		Re: bug in is_numeric By: Luuk on Sun, 12 May 2013 15:58
		Re: bug in is_numeric By: Thomas Mlynarczyk on Sun, 12 May 2013 16:06
		Re: bug in is_numeric By: Denis McMahon on Sun, 12 May 2013 16:24
		Re: bug in is_numeric By: fred on Sun, 12 May 2013 17:41
		Re: bug in is_numeric By: Erwin Moller on Mon, 13 May 2013 11:50
		Re: bug in is_numeric By: fred on Mon, 13 May 2013 13:58
		Re: bug in is_numeric By: Jerry Stuckle on Mon, 13 May 2013 14:11
		Re: bug in is_numeric By: fred on Mon, 13 May 2013 14:15
		Re: bug in is_numeric By: Erwin Moller on Mon, 13 May 2013 15:29
		Re: bug in is_numeric By: J.O. Aho on Mon, 13 May 2013 17:55
		Re: bug in is_numeric By: Richard Yates on Tue, 14 May 2013 13:41
		Re: bug in is_numeric By: SwissCheese on Wed, 15 May 2013 01:43
		Re: bug in is_numeric By: Jerry Stuckle on Wed, 15 May 2013 03:01
		Re: bug in is_numeric By: SwissCheese on Wed, 15 May 2013 09:48
		Re: bug in is_numeric By: Jerry Stuckle on Wed, 15 May 2013 10:11
		Re: bug in is_numeric By: SwissCheese on Thu, 16 May 2013 22:36
		Re: bug in is_numeric By: Thomas 'PointedEars' on Wed, 15 May 2013 13:19
		Re: bug in is_numeric By: Christoph Becker on Wed, 15 May 2013 18:23
		Re: bug in is_numeric By: Thomas 'PointedEars' on Wed, 15 May 2013 18:49
		Re: bug in is_numeric By: Christoph Becker on Wed, 15 May 2013 19:58
		Re: bug in is_numeric By: Thomas 'PointedEars' on Wed, 15 May 2013 20:20
		Re: bug in is_numeric By: Christoph Becker on Wed, 15 May 2013 20:42
		Re: bug in is_numeric By: Thomas Mlynarczyk on Wed, 15 May 2013 21:53
		Re: bug in is_numeric By: Christoph Becker on Wed, 15 May 2013 22:29
		Re: bug in is_numeric By: Christoph Becker on Wed, 15 May 2013 22:40
		Re: bug in is_numeric By: Thomas 'PointedEars' on Thu, 16 May 2013 03:00
		Re: bug in is_numeric By: SwissCheese on Thu, 16 May 2013 22:16
		Re: bug in is_numeric By: Thomas 'PointedEars' on Thu, 16 May 2013 22:45
		Re: bug in is_numeric By: SwissCheese on Fri, 17 May 2013 02:52
		Re: bug in is_numeric By: Thomas 'PointedEars' on Fri, 17 May 2013 16:33
		Re: bug in is_numeric By: Christoph Becker on Fri, 17 May 2013 18:39
		Re: bug in is_numeric By: Thomas 'PointedEars' on Fri, 17 May 2013 21:45
		Re: bug in is_numeric By: Christoph Becker on Sat, 18 May 2013 12:47
		Re: bug in is_numeric By: SwissCheese on Thu, 16 May 2013 00:57
		Re: bug in is_numeric By: Jerry Stuckle on Thu, 16 May 2013 04:09
		Re: bug in is_numeric By: Christoph Becker on Thu, 16 May 2013 23:17
		Re: bug in is_numeric By: Jerry Stuckle on Fri, 17 May 2013 00:30
		Re: bug in is_numeric By: Christoph Becker on Sat, 18 May 2013 12:51
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 14:07
		Re: bug in is_numeric By: Sanders Kaufman on Sat, 18 May 2013 16:56
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 18:32
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sat, 18 May 2013 20:24
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 21:01
		Re: bug in is_numeric By: Denis McMahon on Sat, 18 May 2013 21:58
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 23:21
		Re: bug in is_numeric By: Denis McMahon on Sun, 19 May 2013 02:22
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 02:41
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 10:28
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 13:42
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:42
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 18:39
		Re: bug in is_numeric By: Sanders Kaufman on Tue, 21 May 2013 06:01
		Re: bug in is_numeric By: Jerry Stuckle on Tue, 21 May 2013 09:59
		Re: bug in is_numeric By: The Natural Philosoph on Sun, 19 May 2013 06:49
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 10:31
		Re: bug in is_numeric By: The Natural Philosoph on Sun, 19 May 2013 11:39
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 13:43
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:52
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 18:42
		Re: bug in is_numeric By: Sanders Kaufman on Tue, 21 May 2013 06:03
		Re: bug in is_numeric By: Jerry Stuckle on Tue, 21 May 2013 10:00
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:45
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 10:27
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 13:45
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:37
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 18:43
		Re: bug in is_numeric By: Sanders Kaufman on Tue, 21 May 2013 05:59
		Re: bug in is_numeric By: Jerry Stuckle on Tue, 21 May 2013 10:02
		Re: bug in is_numeric By: Sanders Kaufman on Sat, 18 May 2013 22:08
		Re: bug in is_numeric By: The Natural Philosoph on Sat, 18 May 2013 22:58
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 23:22
		Re: bug in is_numeric By: Sanders Kaufman on Sat, 18 May 2013 22:11
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 23:23
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 10:35
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 13:46
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:23
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 19 May 2013 18:44
		Re: bug in is_numeric By: Sanders Kaufman on Tue, 21 May 2013 05:54
		Re: bug in is_numeric By: Jerry Stuckle on Tue, 21 May 2013 10:03
		Re: bug in is_numeric By: fred on Thu, 23 May 2013 14:38
		Re: bug in is_numeric By: Arno Welzel on Sat, 01 June 2013 15:36
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 01 June 2013 18:54
		Re: bug in is_numeric By: Arno Welzel on Wed, 05 June 2013 13:25
		Re: bug in is_numeric By: Jerry Stuckle on Wed, 05 June 2013 14:34
		Re: bug in is_numeric By: Arno Welzel on Wed, 05 June 2013 15:02
		Re: bug in is_numeric By: Jerry Stuckle on Wed, 05 June 2013 16:30
		OT: What you say is not always what you mean (was: Re: bug in is_numeric) By: Arno Welzel on Wed, 05 June 2013 18:20
		Re: OT: What you say is not always what you mean By: Jerry Stuckle on Wed, 05 June 2013 18:40
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sat, 18 May 2013 19:51
		Re: bug in is_numeric By: Sanders Kaufman on Sat, 18 May 2013 22:13
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sat, 18 May 2013 22:49
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 10:24
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 19 May 2013 10:40
		Re: bug in is_numeric By: The Natural Philosoph on Sun, 19 May 2013 11:43
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 19 May 2013 16:29
		Re: bug in is_numeric By: Norman Peelman on Sat, 18 May 2013 18:53
		Re: bug in is_numeric By: SwissCheese on Thu, 16 May 2013 22:41
		Re: bug in is_numeric By: Daniel Pitts on Mon, 13 May 2013 15:35
		Re: bug in is_numeric By: Denis McMahon on Mon, 13 May 2013 20:26
		Re: bug in is_numeric By: Denis McMahon on Mon, 13 May 2013 20:15
		Re: bug in is_numeric By: Robert Heller on Sun, 12 May 2013 18:03
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 16:03
		Re: bug in is_numeric By: fred on Sun, 12 May 2013 17:34
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 17:40
		Re: bug in is_numeric By: Luuk on Sun, 12 May 2013 19:51
		Re: bug in is_numeric By: Sanders Kaufman on Sun, 12 May 2013 16:47
		Re: bug in is_numeric By: Luuk on Sun, 12 May 2013 16:56
		Re: bug in is_numeric By: Thomas Mlynarczyk on Sun, 12 May 2013 17:05
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 17:38
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 17:46
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 12 May 2013 18:11
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 18:39
		Re: bug in is_numeric By: Jerry Stuckle on Sun, 12 May 2013 20:51
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sun, 12 May 2013 23:27
		Re: bug in is_numeric By: Jerry Stuckle on Mon, 13 May 2013 00:35
		Re: bug in is_numeric By: Thomas 'PointedEars' on Mon, 13 May 2013 09:07
		Re: bug in is_numeric By: Jerry Stuckle on Mon, 13 May 2013 13:02
		Re: bug in is_numeric By: Thomas 'PointedEars' on Mon, 13 May 2013 14:57
		Re: bug in is_numeric By: Thomas 'PointedEars' on Mon, 13 May 2013 15:10
		Re: bug in is_numeric By: Jerry Stuckle on Mon, 13 May 2013 17:52
		Re: bug in is_numeric By: Thomas 'PointedEars' on Mon, 13 May 2013 18:28
		Re: bug in is_numeric By: SwissCheese on Thu, 16 May 2013 22:28
		Re: bug in is_numeric By: Thomas 'PointedEars' on Thu, 16 May 2013 22:33
		Re: bug in is_numeric By: SwissCheese on Fri, 17 May 2013 02:34
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sat, 18 May 2013 08:28
		Re: bug in is_numeric By: Norman Peelman on Sat, 18 May 2013 12:00
		Re: bug in is_numeric By: Luuk on Sat, 18 May 2013 12:18
		Re: bug in is_numeric By: Tim Streater on Sat, 18 May 2013 12:20
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 12:47
		Re: bug in is_numeric By: The Natural Philosoph on Sat, 18 May 2013 13:05
		Re: bug in is_numeric By: Jerry Stuckle on Sat, 18 May 2013 14:16
		Re: bug in is_numeric By: Thomas 'PointedEars' on Sat, 18 May 2013 14:14
		Re: bug in is_numeric By: Sandman on Tue, 14 May 2013 08:34
		Re: bug in is_numeric By: fred on Tue, 14 May 2013 13:47
		Re: bug in is_numeric By: Denis McMahon on Tue, 14 May 2013 14:54
		Re: bug in is_numeric By: Sandman on Wed, 15 May 2013 06:05
		Re: bug in is_numeric By: Jerry Stuckle on Wed, 15 May 2013 10:27
		Re: bug in is_numeric By: Erwin Moller on Wed, 15 May 2013 11:11

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