Merge multi-dimensional array preserving keys

So I have an array as follows. I want to merge all of these into one array of key => value.

key => value

Input :

$logTypes = array(
'user_management' => array(
1001 => 'A new user was added',
1002 => '#user_name# accessed user management',
1003 => 'Created',
1004 => 'Edited/Updated'),
'report_management' => array(
2001 => '#user_name# Added a new report',
2002 => '#user_name# viewed "edit history" for the report #report_name#',
),
);


Required Output :

array (
1001 => 'A new user was added',
1002 => '#user_name# accessed user management',
1003 => 'Created',
1004 => 'Edited/Updated',
2001 => '#user_name# Added a new report',
2002 => '#user_name# viewed "edit history" for the report #report_name#',
)


I tried various permutations of array_merge, array_map, array_values but they just don't work as a whole, like some of them manage to merge but re-index the keys etc. etc.

array_merge

array_map

array_values

My attempts:

logTypes = call_user_func('array_merge', array_values(self::$logTypes));

logTypes = call_user_func('array_merge', array_values(self::$logTypes));

$logTypes = call_user_func('array_push', self::$logTypes);

$logTypes = call_user_func('array_push', self::$logTypes);

$logTypes = call_user_func_array('array_merge', self::$logTypes);

$logTypes = call_user_func_array('array_merge', self::$logTypes);

$logTypes = array_values(array_values(self::$logTypes));

$logTypes = array_values(array_values(self::$logTypes));

$array = array_map('current', self::$logTypes);

$array = array_map('current', self::$logTypes);

$merged = array_merge(...self::$logTypes);

$merged = array_merge(...self::$logTypes);

Finally I had to resort to what I was trying to avoid all along, looping through each array :l

$plain_array = array();
foreach (self::$logTypes as $types) {
$plain_array += $types;
}


It works, so now my question is that, Is there any other way to achieve the desired result, using the above array_* functions ?

If I may add, may the shortest solution win!! :)

array_replace

$plain_array = array(); foreach ($logTypes as $types) { $plain_array = array_replace($plain_array, $types); }

array_reduce( $logTypes, function($carry, $types) { $carry = array_replace($carry, $types); return $carry; }, );

array_reduce(self::$logTypes, function($carry, $types) { return $carry += $types; }, )

3 Answers
3

You can do it like this:

array_reduce($logTypes, function($carry, $item) {
return $carry + $item;
}, );


output:

array (
1001 => 'A new user was added',
1002 => '#user_name# accessed user management',
1003 => 'Created',
1004 => 'Edited/Updated',
2001 => '#user_name# Added a new report',
2002 => '#user_name# viewed "edit history" for the report #report_name#',
)


Source: http://php.net/manual/en/function.array-reduce.php

<?php
$logTypes = array(
'user_management' => array(
1001 => 'A new user was added',
1002 => '#user_name# accessed user management',
1003 => 'Created',
1004 => 'Edited/Updated'),
'report_management' => array(
2001 => '#user_name# Added a new report',
2002 => '#user_name# viewed "edit history" for the report #report_name#',
),
);
$emp_arr = array();
foreach ($logTypes as $data)
{
$Output = array_replace($emp_arr, $data);
}
print_R ($Output);
?>

== Output
Array
(
[1001] => A new user was added
[1002] => #user_name# accessed user management
[1003] => Created
[1004] => Edited/Updated
[2001] => #user_name# Added a new report
[2002] => #user_name# viewed "edit history" for the report #report_name#
)


Try this:

$new_array = $logTypes['user_management'] + $logTypes['report_management'];


PHP doc

If you want to append array elements from the second array to the first array while not overwriting the elements from the first array and not re-indexing, use the + array union operator

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