Merge em all
There are quite a few functions and methods available:
The produce different results. So it's good to know when which of those merging methods should be best used. See for yourself.The two arrays we want to merge:
Array ( [root] => Array ( [deep1] => Array ( [deeper1a] => value1a [deeper2b] => value2b ) [deep2] => Array (  => deeper1  => deeper2 ) [deep3] => stringX ) )
Array ( [root] => Array ( [deep1] => Array ( [deeper1a] => value1a [deeper3b] => value3b ) [deep2] => Array (  => deeper1  => deeper3 ) [deep3] => stringY ) )
- am() is useful if some arrays can be simple strings. This avoids notices thrown. This is irrevelant when it's clear that the input is an array.
- array_merge_recursive() is value oriented. It ignores keys and merge-adds values regardless if they already exist.
- array_merge() is more key oriented. If the same key exists, it will be overwritten.
- Hash::merge() is somewhere in the middle and behaves a little bit more key oriented while trying to keep values as well.