array_count_values
I've worked on array_diff_assoc_recursive() mentioned by chinello at gmail dot com and I think it might be worth mentioning here. I wrote a dozen test cases and it seems to be holding up pretty well.
<?php
// dwarven Differences:
// * Replaced isset() with array_key_exists() to account for keys with null contents
// 55 dot php at imars dot com Differences:
// Key differences:
// * Removed redundant test;
// * Returns false bool on exact match (not zero integer);
// * Use type-precise comparison "!==" instead of loose "!=";
// * Detect when $array2 contains extraneous elements;
// * Returns "before" and "after" instead of only "before" arrays on mismatch.
function array_compare($array1, $array2) {
$diff = false;
// Left-to-right
foreach ($array1 as $key => $value) {
if (!array_key_exists($key,$array2)) {
$diff[0][$key] = $value;
} elseif (is_array($value)) {
if (!is_array($array2[$key])) {
$diff[0][$key] = $value;
$diff[1][$key] = $array2[$key];
} else {
$new = array_compare($value, $array2[$key]);
if ($new !== false) {
if (isset($new[0])) $diff[0][$key] = $new[0];
if (isset($new[1])) $diff[1][$key] = $new[1];
};
};
} elseif ($array2[$key] !== $value) {
$diff[0][$key] = $value;
$diff[1][$key] = $array2[$key];
};
};
// Right-to-left
foreach ($array2 as $key => $value) {
if (!array_key_exists($key,$array1)) {
$diff[1][$key] = $value;
};
// No direct comparsion because matching keys were compared in the
// left-to-right loop earlier, recursively.
};
return $diff;
};
?>
Note that to catch small type differences, you need to use var_dump() rather than print_r(). For example:
<?php
first = Array( 'first' => 'second', 'third' => 'fourth',
'fifth' => Array( 'oui' => 'yes', 'non' => 'no' ),
'sixth' => Array( 3, 4, 2, 1 )
);
$second = Array( 'first' => 'second', 'third' => 'fourth',
'fifth' => Array( 'oui' => 'yes', 'non' => 'no' ),
'sixth' => Array( 3, 4, '2', 1 )
);
$diff = array_compare($first, $second);
if ($diff === false) echo "MATCH\n";
else var_dump($diff);
?>
The above would immediately show that element "sixth", index 2, is int(2) in $first but string(1)"2" in $second. As per the original function, order for associative arrays does not matter, and of course it does with lists.
[EDIT: Credits to php dot notes at dwarven dot co dot uk]
array_diff_assoc
(PHP 4 >= 4.3.0, PHP 5)
array_diff_assoc — Computa a diferença entre arrays com checagem adicional de índice
Descrição
array array_diff_assoc
( array $array1
, array $array2
[, array $...
] )
Compara array1 com array2 e retorna a diferença. Ao contrário de array_diff(), as chaves dos arrays são usadas na comparação.
Parâmetros
- array1
-
O array a comparar.
- array2
-
O array a ser comparado.
- ...
-
Mais arrays a serem comparados.
Valor Retornado
Retorna um array contendo todos os valores do array1 que não estão presentes em qualquer dos outros arrays.
Exemplos
Exemplo #1 Exemplo de array_diff_assoc()
Neste exemplo você vê que o par "a" => "verde" está presente em ambos os arrays e assim ele não está na saída da função. Ao contrário disso, o par 0 => "vermelho" está na saída porque no segundo argumento "vermelho" tem a chave 1.
<?php
$array1 = array("a" => "verde", "b" => "marrom", "c" => "azul", "vermelho");
$array2 = array("a" => "verde", "amarelo", "vermelho");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
O exemplo acima irá imprimir:
Array
(
[b] => marrom
[c] => azul
[0] => vermelho
)
Exemplo #2 Exemplo de array_diff_assoc()
Dois valores dos pares chave => valor são considerados iguais somente se (string) $elem1 === (string) $elem2 . Em outras palavras, uma checagem estrita de string é feita para que representações de string sejam as mesmas.
<?php
$array1 = array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
O exemplo acima irá imprimir:
Array
(
[0] => 0
[1] => 1
)
Notas
Nota: Esta função checa somente uma dimensão de um array n-dimensional. É claro que você pode checar dimensões mais profundas usando, por exemplo, array_diff_assoc($array1[0], $array2[0]);.
Veja Também
- array_diff() - Analisa as diferenças entre arrays
- array_intersect() - Calcula a interseção entre arrays
- array_intersect_assoc() - Computa a interseção de arrays com uma adicional verificação de índice
add a note
User Contributed Notesarray_diff_assoc
55 dot php at imars dot com
17-Mar-2009 01:09
17-Mar-2009 01:09
jrajpu10 at gmail dot com
25-Oct-2008 05:57
25-Oct-2008 05:57
array_diff_assoc can also be used to find the duplicates in an array
<?php
$arr = array('1','2','3','4','3','2','5');
$uniques = array_unique($arr);
// array_diff will not work here, array_diff_assoc works as it takes the key // in account.
$dups = array_diff_assoc($arr, $uniques);
print_r($dups);
?>
Note: The index of the $dups is not in strict sequential order as expected by C programmer.
cedric at daneel dot net
21-May-2007 11:01
21-May-2007 11:01
To diff between n-dimensional array, juste use this :
<?php
function array_diff_values($tab1, $tab2)
{
$result = array();
foreach($tab1 as $values) if(! in_array($values, $tab2)) $result[] = $values;
return $result;
}
?>
contact at pascalopitz dot com
11-Apr-2007 09:14
11-Apr-2007 09:14
The direction of the arguments does actually make a difference:
<?php
$a = array(
'x' => 'x',
'y' => 'y',
'z' => 'z',
't' => 't',
);
$b = array(
'x' => 'x',
'y' => 'y',
'z' => 'z',
't' => 't',
'g' => 'g',
);
print_r(array_diff_assoc($a, $b));
print_r(array_diff_assoc($b, $a));
?>
echoes:
Array
(
)
Array
(
[g] => g
)
chinello at gmail dot com
19-Mar-2007 04:33
19-Mar-2007 04:33
The following will recursively do an array_diff_assoc, which will calculate differences on a multi-dimensional level. This not display any notices if a key don't exist and if error_reporting is set to E_ALL:
<?php
function array_diff_assoc_recursive($array1, $array2)
{
foreach($array1 as $key => $value)
{
if(is_array($value))
{
if(!isset($array2[$key]))
{
$difference[$key] = $value;
}
elseif(!is_array($array2[$key]))
{
$difference[$key] = $value;
}
else
{
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if($new_diff != FALSE)
{
$difference[$key] = $new_diff;
}
}
}
elseif(!isset($array2[$key]) || $array2[$key] != $value)
{
$difference[$key] = $value;
}
}
return !isset($difference) ? 0 : $difference;
}
?>
[NOTE BY danbrown AT php DOT net: This is a combination of efforts from previous notes deleted. Contributors included (Michael Johnson), (jochem AT iamjochem DAWT com), (sc1n AT yahoo DOT com), and (anders DOT carlsson AT mds DOT mdh DOT se).]
Alexander Podgorny
30-May-2006 07:30
30-May-2006 07:30
NOTE: the diff_array also removes all the duplicate values that match to the values in the second array:
<?php
$array1 = array("a","b","c","a","a");
$array2 = array("a");
$diff = array_diff($array1,$array2);
// yields: array("b","c") the duplicate "a" values are removed
?>
benjamin at moonfactory dot co dot jp
12-Jan-2005 03:56
12-Jan-2005 03:56
Hi all,
For php versions < 4.3...
<?php
/**
* array_diff_assoc for version < 4.3
**/
if (!function_exists('array_diff_assoc'))
{
function array_diff_assoc($a1, $a2)
{
foreach($a1 as $key => $value)
{
if(isset($a2[$key]))
{
if((string) $value !== (string) $a2[$key])
{
$r[$key] = $value;
}
}else
{
$r[$key] = $value;
}
}
return $r ;
}
}
?>
carl at thep dot lu dot se
09-May-2003 07:55
09-May-2003 07:55
To unset elements in an array if you know the keys but not the values, you can do:
<?php
$a = array("foo", "bar", "baz", "quux");
$b = array(1, 3); // Elements to get rid of
foreach($b as $e)
unset($a[$e]);
?>
Of course this makes most sense if $b has many elements or is dynamically generated.