Deep merging two arrays in PHP

February 4th, 2010 | Posted in PHP

PHP has a wealth of functions for manipulating arrays, however; I often want to deep merge 2 arrays whilst maintaining the key => value structure. PHP does have functions that will merge multiple arrays but they attempt to maintain duplicate keys.

The below function take 2 arguments (arrays). Arguments are in order of importance, the second arguments values will always overwrite the first arguments values and so on.

function array_merge_replace($base_array, $merge_array){
	$new_array = array();
	$key_list = array_merge((array)$base_array, (array)$merge_array);
	foreach($key_list as $k=&gt;$v){
		if(is_array($base_array[$k])||is_array($merge_array[$k])){
			$new_array[$k] = array_merge_replace($base_array[$k], $merge_array[$k]);
		}else{
			$new_array[$k] = $merge_array[$k] ? $merge_array[$k] : $base_array[$k];
		}
	}
	return $new_array;
}

This entry was posted on Thursday, February 4th, 2010 at 1:22 pm. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

Partizanas | June 14, 2010 at 11:42 pm

Dude! Have you tested this? Next time use phpUnit or smth…
This is a littel correction:

function array_deep_merge($base_array, $merge_array)
{
$result = array();
$result = array_merge((array)$base_array, (array)$merge_array);

foreach($result as $k => $v)
{
if(isset($base_array[$k]) && is_array($base_array[$k]) && isset($merge_array[$k]))
{
$result[$k] = array_deep_merge($base_array[$k], $merge_array[$k]);
}
elseif(isset($merge_array[$k]) && is_array($merge_array[$k]) && isset($base_array[$k]))
{
$result[$k] = array_deep_merge($base_array[$k], $merge_array[$k]);
}
}

return $result;
}

WP Themes | August 2, 2010 at 10:06 pm

Genial fill someone in on and this enter helped me alot in my college assignement. Thank you on your information.

Matt Lowden