[PHP] Re: unexpected array_diff output
Frederic Noyer [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hello there !
I am trying to fill and then compare two arrays: one filled by a
foreach construct, and the second by a while construct.
I check both with a print_r to be sure that both are correctly filled
(which seems to be the case). But then, when I try to compare them with
a array_diff , the result is incoherent (at least to me...). I have
tried several variant, but I don't understand what's wrong. Sure you
guys can tell me where is my mistake.
Here is the code:
?
// creates first array (from a _POST[''] )
foreach ($_POST['input_auteur'] AS $aut_ligne) {
$part_ligne = explode(,,$aut_ligne);
$arr1[] = (string) $part_ligne['2'];
}
echo Array from POST :;
print_r ($arr1);
// creates second array (from SQL query)
$sqlListAut = 'SELECT aut_id FROM mr_ecrit WHERE doc_id = ' .
$_GET['docu'];
$resultListAut = mysql_query($sqlListAut);
while ($recListAut = mysql_fetch_array($resultListAut)) {
$arr2[] = (string) $recListAut['aut_id'];
}
echo Array from SQL:BR;
print_r ($arr2);
// comparing both arrays to detect if there is elements in the first
array which are not present in the second array $result =
array_diff($arr1, $arr2);
echo array_diff results :;
print_r($result);
?
Here is a typical output:
__
Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 )
Array from SQL : Array ( [0] = 3 [1] = 4 )
**
array_diff results : Array ( [0] = 2 [1] = 3 [2] = 4 )
__
As you can see, the array_diff seems to always return all elements of
the first array.
I think this is correct because the 3 key/value pairs from the first array
are NOT in the second one. I think the combination of key and value are
relevant for array_diff().
So if you had:
Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 )
Array from SQL : Array ( [0] = 2 [1] = 3 )
**
The diff would be:
array_diff results : Array ( [2] = 4 )
Regards, Torsten
Thanks for your help.
Best regards,
Fred Noyer
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Re: [PHP] Re: unexpected array_diff output
On 30 avr. 04, at 11:00, Torsten Roehr wrote:
Frederic Noyer [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hello there !
I am trying to fill and then compare two arrays: one filled by a
foreach construct, and the second by a while construct.
I check both with a print_r to be sure that both are correctly filled
(which seems to be the case). But then, when I try to compare them
with
a array_diff , the result is incoherent (at least to me...). I have
tried several variant, but I don't understand what's wrong. Sure you
guys can tell me where is my mistake.
Here is the code:
?
// creates first array (from a _POST[''] )
foreach ($_POST['input_auteur'] AS $aut_ligne) {
$part_ligne = explode(,,$aut_ligne);
$arr1[] = (string) $part_ligne['2'];
}
echo Array from POST :;
print_r ($arr1);
// creates second array (from SQL query)
$sqlListAut = 'SELECT aut_id FROM mr_ecrit WHERE doc_id = ' .
$_GET['docu'];
$resultListAut = mysql_query($sqlListAut);
while ($recListAut = mysql_fetch_array($resultListAut)) {
$arr2[] = (string) $recListAut['aut_id'];
}
echo Array from SQL:BR;
print_r ($arr2);
// comparing both arrays to detect if there is elements in the first
array which are not present in the second array $result =
array_diff($arr1, $arr2);
echo array_diff results :;
print_r($result);
?
Here is a typical output:
__
Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 )
Array from SQL : Array ( [0] = 3 [1] = 4 )
**
array_diff results : Array ( [0] = 2 [1] = 3 [2] = 4 )
__
As you can see, the array_diff seems to always return all elements of
the first array.
I think this is correct because the 3 key/value pairs from the first
array
are NOT in the second one. I think the combination of key and value are
relevant for array_diff().
So if you had:
Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 )
Array from SQL : Array ( [0] = 2 [1] = 3 )
**
The diff would be:
array_diff results : Array ( [2] = 4 )
Ok, but when I give the function this input
Array from POST: Array ( [0] = 2 )
Array from SQL : Array ( [0] = 2 )
The output I get is:
the diff between both : Array ( [0] = 2 )
Why is it not and empty output ? Which is not what I have understand
the array_diff should do (or maybe I didn't understand what the
function should do).
Thanks again for your kind help,
Frederic Noyer
PS: version of PHP is 4.3
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Re: [PHP] Re: unexpected array_diff output
On 30 avr. 04, at 11:00, Torsten Roehr wrote: I think this is correct because the 3 key/value pairs from the first array are NOT in the second one. I think the combination of key and value are relevant for array_diff(). As I have understand only the array_diff_assoc function does that. see php.net: Description array array_diff_assoc ( array array1, array array2 [, array ...]) array_diff_assoc() returns an array containing all the values from array1 that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff(). Fred So if you had: Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 ) Array from SQL : Array ( [0] = 2 [1] = 3 ) ** The diff would be: array_diff results : Array ( [2] = 4 ) Regards, Torsten -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: unexpected array_diff output
Frederic Noyer [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 30 avr. 04, at 11:00, Torsten Roehr wrote: I think this is correct because the 3 key/value pairs from the first array are NOT in the second one. I think the combination of key and value are relevant for array_diff(). As I have understand only the array_diff_assoc function does that. see php.net: Description array array_diff_assoc ( array array1, array array2 [, array ...]) array_diff_assoc() returns an array containing all the values from array1 that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff(). So array_diff() seems to be for arrays where the key is not defined so that only values are recognized. Regards, Torsten Fred So if you had: Array from POST: Array ( [0] = 2 [1] = 3 [2] = 4 ) Array from SQL : Array ( [0] = 2 [1] = 3 ) ** The diff would be: array_diff results : Array ( [2] = 4 ) Regards, Torsten -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: unexpected array_diff output
On 30 avr. 04, at 11:31, Torsten Roehr wrote: Frederic Noyer [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 30 avr. 04, at 11:00, Torsten Roehr wrote: I think this is correct because the 3 key/value pairs from the first array are NOT in the second one. I think the combination of key and value are relevant for array_diff(). As I have understand only the array_diff_assoc function does that. see php.net: Description array array_diff_assoc ( array array1, array array2 [, array ...]) array_diff_assoc() returns an array containing all the values from array1 that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff(). So array_diff() seems to be for arrays where the key is not defined so that only values are recognized. Regards, Torsten Any ideas what this implies in termes of code ? You mean, I should not fill my array with values this way ? $arr2[] = (string) $recListAut['aut_id']; Because this is precisely the way to fill it without specifying the key. see www.php.net: http://ch2.php.net/manual/en/language.types.array.php Regards, Fred -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Re: unexpected array_diff output
Frederic Noyer [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 30 avr. 04, at 11:31, Torsten Roehr wrote: Frederic Noyer [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 30 avr. 04, at 11:00, Torsten Roehr wrote: I think this is correct because the 3 key/value pairs from the first array are NOT in the second one. I think the combination of key and value are relevant for array_diff(). As I have understand only the array_diff_assoc function does that. see php.net: Description array array_diff_assoc ( array array1, array array2 [, array ...]) array_diff_assoc() returns an array containing all the values from array1 that are not present in any of the other arguments. Note that the keys are used in the comparison unlike array_diff(). So array_diff() seems to be for arrays where the key is not defined so that only values are recognized. Regards, Torsten Any ideas what this implies in termes of code ? You mean, I should not fill my array with values this way ? $arr2[] = (string) $recListAut['aut_id']; If the keys are not important for you that would be the way to do it, although I don't think you need (string). If the keys are important you should use array_diff_assoc(). Regards, Torsten Because this is precisely the way to fill it without specifying the key. see www.php.net: http://ch2.php.net/manual/en/language.types.array.php Regards, Fred -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
