array_udiff_uassoc
It is not stated, by this function also diffs array1 to itself, removing any duplicate values...
array_udiff
(PHP 5)
array_udiff — Vypočíta rozdiel polí pomocou callback funkcie pre dátové porovnávanie.
Popis
array array_udiff
( array $array1
, array $array2
[, array $ ...
], callback $data_compare_func
)
array_udiff() vracia pole obsahujúce všetky hodnoty v array1 , ktoré sa nenachádzajú v žiadnom inom argumente. Upozorňujeme, že kľúče sa zachovávajú. Na porovnávanie dát je použitá data_compare_func . Musí vrátiť integer menší než, rovný, alebo väčší než nula, ak je prvý argument považovaný v poradí za menší než, rovný, alebo väčší než druhý. V tomto je odlišnosť od array_diff(), ktorá na porovnávanie dát používa vnútornú funkciu.
Example#1 array_udiff() príklad
<?php
class cr {
private $priv_member;
function cr($val)
{
$this->priv_member = $val;
}
function comp_func_cr($a, $b)
{
if ($a->priv_member === $b->priv_member) return 0;
return ($a->priv_member > $b->priv_member)? 1:-1;
}
}
$a = array("0.1" => new cr(9), "0.5" => new cr(12), 0 => new cr(23), 1=> new cr(4), 2 => new cr(-15),);
$b = array("0.2" => new cr(9), "0.5" => new cr(22), 0 => new cr(3), 1=> new cr(4), 2 => new cr(-15),);
$result = array_udiff($a, $b, array("cr", "comp_func_cr"));
print_r($result);
?>
Výsledok je:
Array ( [0.5] => cr Object ( [priv_member:private] => 12 ) [0] => cr Object ( [priv_member:private] => 23 ) )
Note: Dva prvky sa považujú za zhodné vtedy a len vtedy ak (string) $elem1 === (string) $elem2. Slovami: keď je reprezentácia reťazca rovnaká.
Note: Upozorňujeme vás na to, že funkcia kontroluje iba jednu dimenziu n-dimenzionálneho poľa. Samozrejme, môžete kontrolovať i hlbšie dimenzie pomocou array_udiff($array1[0], $array2[0], "data_compare_func");.
Tiež pozri array_diff(), array_diff_assoc(), array_diff_uassoc(), array_udiff_assoc(), array_udiff_uassoc(), array_intersect(), array_intersect_assoc(), array_uintersect(), array_uintersect_assoc() a array_uintersect_uassoc().
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User Contributed Notesarray_udiff
adam dot jorgensen dot za at gmail dot com
08-Oct-2008 06:51
08-Oct-2008 06:51
grantwparks at gmail dot com
31-Dec-2007 07:15
31-Dec-2007 07:15
Re: "convoluted"
I think the point being made is that array_udiff() can be used not only for comparisons between homogenous arrays, as in your example (and definitely the most common need), but it can be used to compare heterogeneous arrays, too.
Consider:
<?php
function compr_1($a, $b) {
$aVal = is_array($a) ? $a['last_name'] : $a;
$bVal = is_array($b) ? $b['last_name'] : $b;
return strcasecmp($aVal, $bVal);
}
$aEmployees = array(
array('last_name' => 'Smith',
'first_name' => 'Joe',
'phone' => '555-1000'),
array('last_name' => 'Doe',
'first_name' => 'John',
'phone' => '555-2000'),
array('last_name' => 'Flagg',
'first_name' => 'Randall',
'phone' => '666-1000')
);
$aNames = array('Doe', 'Smith', 'Johnson');
$result = array_udiff($aEmployees, $aNames, "compr_1");
print_r($result);
?>
Allowing me to get the "employee" that's not in the name list:
Array ( [2] => Array ( [last_name] => Flagg [first_name] => Randall [phone] => 666-1000 ) )
Something interesting to note, is that the two arguments to the compare function don't correspond to array1 and array2. That's why there has to be logic in it to handle that either of the arguments might be pointing to the more complex employee array. (Found this out the hard way.)
Colin
02-Aug-2006 01:15
02-Aug-2006 01:15
I think the example given here using classes is convoluting things too much to demonstrate what this function does.
array_udiff() will walk through array_values($a) and array_values($b) and compare each value by using the passed in callback function.
To put it another way, array_udiff() compares $a[0] to $b[0], $b[1], $b[2], and $b[3] using the provided callback function. If the callback returns zero for any of the comparisons then $a[0] will not be in the returned array from array_udiff(). It then compares $a[1] to $b[0], $b[1], $b[2], and $b[3]. Then, finally, $a[2] to $b[0], $b[1], $b[2], and $b[3].
For example, compare_ids($a[0], $b[0]) === -5 while compare_ids($a[1], $b[1]) === 0. Therefore, $a[1] is not returned from array_udiff() since it is present in $b.
<?
$a = array(
array(
'id' => 10,
'name' => 'John',
'color' => 'red',
),
array(
'id' => 20,
'name' => 'Elise',
'color' => 'blue',
),
array(
'id' => 30,
'name' => 'Mark',
'color' => 'red',
),
);
$b = array(
array(
'id' => 15,
'name' => 'Nancy',
'color' => 'black',
),
array(
'id' => 20,
'name' => 'Elise',
'color' => 'blue',
),
array(
'id' => 30,
'name' => 'Mark',
'color' => 'red',
),
array(
'id' => 40,
'name' => 'John',
'color' => 'orange',
),
);
function compare_ids($a, $b)
{
return ($a['id'] - $b['id']);
}
function compare_names($a, $b)
{
return strcmp($a['name'], $b['name']);
}
$ret = array_udiff($a, $b, 'compare_ids');
var_dump($ret);
$ret = array_udiff($b, $a, 'compare_ids');
var_dump($ret);
$ret = array_udiff($a, $b, 'compare_names');
var_dump($ret);
?>
Which returns the following.
In the first return we see that $b has no entry in it with an id of 10.
<?
array(1) {
[0]=>
array(3) {
["id"]=>
int(10)
["name"]=>
string(4) "John"
["color"]=>
string(3) "red"
}
}
?>
In the second return we see that $a has no entry in it with an id of 15 or 40.
<?
array(2) {
[0]=>
array(3) {
["id"]=>
int(15)
["name"]=>
string(5) "Nancy"
["color"]=>
string(5) "black"
}
[3]=>
array(3) {
["id"]=>
int(40)
["name"]=>
string(4) "John"
["color"]=>
string(6) "orange"
}
}
?>
In third return we see that all names in $a are in $b (even though the entry in $b whose name is 'John' is different, the anonymous function is only comparing names).
<?
array(0) {
}
?>
dmhouse at gmail dot com
20-Jan-2005 01:44
20-Jan-2005 01:44
Very easy way of achieving a case-insensitive version of array_diff (or indeed array_diff_assoc, array_intersect or any of these types of functions which have a similar function that takes a callback function as one of their parameters):
array_udiff($array1, $array2, 'strcasecmp');
This works because strcasecmp() compares two strings case-insensitively, as compared to the array_diff() which compares two strings by using the == operator, which is case-sensitive.
aidan at php dot net
28-May-2004 07:11
28-May-2004 07:11
This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_Compat