RE: [PHP] FILTER_VALIDATE_INT - newbie question

On Wed, 2009-10-07 at 12:03 +0100, MEM wrote: > > Well, it was only a guess, but if you look at the integer limit on 32-bit systems, > > you'll see that the upper limit > for numbers is 2147483647 (or 2^31-1) which would explain > > maybe your upper limit problem. > > > > Also, I think you're getting confused over the zero with exactly what you are asking > > PHP to do. filter_var() returns > true if the filter matches. If the 0 match is returned as a > > false, then filter_var() will return false.. You're then > inverting that with a !, all of > > which is inside an if() statement. Essentially this would mean that if the filter > returns false > > then the instructions inside of the if statement are carried out. > > > I always thought that that was a limit of the number of digits an integer value could have, and > not the actually int value... I guess I was wrong. :s > > You are right, I've tested with: > 2147483647 > it worked. > > I've tested with: > 2147483648 > It displays the error. > > "you're getting confused over the zero with exactly what you are asking PHP to > do" > Absolutely... :( > > If I put 0 filter_var() will return false. > If I put 0342352 filter_var() will also return false. > > Could we say that: if it is indeed the fact, that filter_var() returns false when it finds a 0 > at the beginning of a given number... > > "then the instructions inside of the if statement are carried out." > > And here may be the reason for displaying the error message when we have the 0 leading a > number. > > And my point was exactly here > "If the 0 match is returned as a false" > > Why should filter_var() do something like this? Should the filter_var() interpretate 0 as a > number without boolean semantic value? > > > Please be patient... > Regards, > Márcio > Imho it shouldn't behave like this. 01 is equally as valid as 1 as far as numbers go, we just ignore leading 0's on any number unless they are in a significant position (i.e. 0.1) I am also surprised to see that while it converts the value to an integer, it doesn't seem to do that first, because 01 is a valid integer: <?php $i = 0; $j = 01; var_dump($i); var_dump($j); ?> The output returns: int(0) int(1) So the filter seems to be doing some form of check on leading zero's before checking the validity of the number! Thanks, Ash http://www.ashleysheridan.co.uk