calculate the difference between two array - php

Question

In PHP, how can I compare two array and get result in a third array ?
This result must contain old and new values. The goal is to display an HTML table with a header like "field | old value | new value" as this, the user can compare all values one by one.
First array :
$array1 = array(
'key1' => array(
'key1.1' => 'value',
'key1.2' => 'value',
),
'key2' => array(
'key2.1' => 'value',
'key2.2' => 'value',
),
'key3' => array(
array('key3.1' => 'value'),
array('key3.2' => 'value'),
),
);
Second array :
$array2 = array(
'key1' => array(
'key1.1' => 'value',
'key1.2' => 'value',
),
'key2' => array(
'key2.1' => 'value',
'key2.2' => 'value',
),
'key3' => array(
array('key3.1' => 'value'),
array('key3.2' => 'value'),
),
);
What I expect :
$results = array(
'key1' => array(
'key1.1' => array(
'old' => 'old_value',
'new' => 'new_value',
),
'key1.2' => array(
'old' => 'old_value',
'new' => 'new_value',
),
),
'key2' => array(
'key2.1' => array(
'old' => 'old_value',
'new' => 'new_value',
),
'key2.2' => array(
'old' => 'old_value',
'new' => 'new_value',
),
),
'key3' => array(
array(
'key3.1' => array(
'old' => 'old_value',
'new' => 'new_value')
),
array(
'key3.1' => array(
'old' => 'old_value',
'new' => 'new_value'),
)
),
);
What I have already tried without success :
function array_diff_assoc_recursive($array1, $array2) {
$exclude = array(
'custom_key'
);
$difference = array();
foreach($array1 as $key => $value) {
if(is_array($value)){
if( !isset($array2[$key]) || !is_array($array2[$key]) ) {
if(!in_array($key,$exclude)){
$difference[$key]['old'] = $value;
$difference[$key]['new'] = $array2[$key];
}
} else {
$new_diff = array_diff_assoc_recursive($value, $array2[$key]);
if(!empty($new_diff))
$difference[$key] = $new_diff;
}
} else if(!array_key_exists($key,$array2) || $array2[$key] !== $value) {
if(!in_array($key,$exclude)){
$difference[$key]['old'] = $value;
$difference[$key]['new'] = $array2[$key];
}
}
}
return $difference;
}

Answer 1

try this code, i'm sure this will work for you
<?php
echo "<pre>";
$array1 = array(
'key1' => array(
'key1.1' => 'aaa',
'key1.2' => 'xxx',
'key1.3' => 'vvv',
),
'key2' => array(
'key2.1' => 'eee',
'key2.2' => 'fff',
'key2.3' => 'ggg',
),
) ;
echo "Array 1: </br>";
print_r($array1);
$array2 = array(
'key1' => array(
'key1.1' => 'aaa',
'key1.2' => 'ddd',
'key1.3' => 'ccc',
),
'key2' => array(
'key2.1' => 'hhh',
'key2.2' => 'fff',
'key2.3' => 'ttt',
),
);
echo "Array 2:</br>";
print_r($array2);
$result='';
foreach($array1 as $key=> $val)
{
foreach($val as $k=> $v)
{
if($v != $array2[$key][$k])
{
$result[$key][$k]['old']= $array2[$key][$k] ;
$result[$key][$k]['new']= $v;
}
}
}
echo "Compared Result: </br>";
echo "<pre>"; print_r($result);
?>
This will Output
Array 1:
Array
(
[key1] => Array
(
[key1.1] => aaa
[key1.2] => xxx
[key1.3] => vvv
)
[key2] => Array
(
[key2.1] => eee
[key2.2] => fff
[key2.3] => ggg
)
)
Array 2:
Array
(
[key1] => Array
(
[key1.1] => aaa
[key1.2] => ddd
[key1.3] => ccc
)
[key2] => Array
(
[key2.1] => hhh
[key2.2] => fff
[key2.3] => ttt
)
)
Compared Result:
Array
(
[key1] => Array
(
[key1.2] => Array
(
[old] => ddd
[new] => xxx
)
[key1.3] => Array
(
[old] => ccc
[new] => vvv
)
)
[key2] => Array
(
[key2.1] => Array
(
[old] => hhh
[new] => eee
)
[key2.3] => Array
(
[old] => ttt
[new] => ggg
)
)
)

Answer 2

Prepare arrays using array_walk_recursive, and combine them. Please note that the original arrays will be changed
array_walk_recursive($array1, function(&$i) { if(!is_array($i)) $i = array('old'=> $i); });
array_walk_recursive($array2, function(&$i) { if(!is_array($i)) $i = array('new'=> $i); });
print_r(array_merge_recursive($array1, $array2));
demo