PHP: merge two arrays while keeping keys instead of reindexing?

Question

How can I merge two arrays (one with string => value pairs and another with int => value pairs) while keeping the string/int keys? None of them will ever overlap (because one has only strings and the other has only integers).

Here is my current code (which doesn't work, because array_merge is re-indexing the array with integer keys):

// get all id vars by combining the static and dynamic $staticIdentifications = array(  Users::userID => "USERID",  Users::username => "USERNAME" ); // get the dynamic vars, formatted: varID => varName $companyVarIdentifications = CompanyVars::getIdentificationVarsFriendly($_SESSION['companyID']); // merge the static and dynamic vars (*** BUT KEEP THE INT INDICES ***) $idVars = array_merge($staticIdentifications, $companyVarIdentifications); 

Answer 1

You can simply 'add' the arrays:

>> $a = array(1, 2, 3); array (   0 => 1,   1 => 2,   2 => 3, ) >> $b = array("a" => 1, "b" => 2, "c" => 3) array (   'a' => 1,   'b' => 2,   'c' => 3, ) >> $a + $b array (   0 => 1,   1 => 2,   2 => 3,   'a' => 1,   'b' => 2,   'c' => 3, ) 

Answer 2

Considering that you have

$replaced = array('1' => 'value1', '4' => 'value4'); $replacement = array('4' => 'value2', '6' => 'value3'); 

Doing $merge = $replacement + $replaced; will output:

Array('4' => 'value2', '6' => 'value3', '1' => 'value1'); 

The first array from sum will have values in the final output.

Doing $merge = $replaced + $replacement; will output:

Array('1' => 'value1', '4' => 'value4', '6' => 'value3');