advanced unset the value form array PHP - php

Question

I have two arrays, what consist arrays. I need to merge these arrays recursive. But I need to do this action few times, and
array_merge_recursive()
will apend my data twice, I want to remove element what already exist in target array.
$messages array :
array(2) {
["messages"]=>
array(2) {
["test.testik"]=>
string(13) "Це тест"
["test2313.tes31231tik"]=>
string(23) "це тестончик"
}
["validators"]=>
array(4) {
["valid.validik"]=>
string(36) "Це валідне значення"
["joga.jimbo"]=>
string(27) "Джімбо торбінс"
["validka.invalidka"]=>
string(23) "це інвалідка"
["smith.john"]=>
string(17) "джон сміт"
}
}
$allCar array:
array(2) {
["messages"]=>
array(1) {
["test2313.tes31231tik"]=>
string(23) "це тестончик"
}
["validators"]=>
array(2) {
["validka.invalidka"]=>
string(23) "це інвалідка"
["smith.john"]=>
string(17) "джон сміт"
}
}
I wrote some code:
foreach ($messages as $domain => $messagesArray) {
foreach ($allCat as $d => $mess) {
if ($domain == $d) {
foreach ($messagesArray as $ymlkey => $trans) {
foreach ($mess as $ymlk => $transl) {
if ($ymlkey == $ymlk) {
unset($mess[$ymlk]);
}
}
}
}
}
}
Then when I run recursive merge it append the same values to array. What I am doing wrong ?

Answer 1

This:
foreach ($allCat as $d => $mess) {
$mess is a temporary COPY of whatever value your foreach() loop is currently working on. When you do your unset($mess...) later on, you're simply unsetting that temporary copy.
While some might suggest making $mess a reference, this can/will cause problems later on, because $mess will STILL be a reference after the loops end, and reusing the variable later on will now be mucking around with whatever $mess last pointed at in the loop.
Instead, use the full array/object path reference in the unset call:
unset($messages[$domain][$d][$ymlkey][$ymkl])
or whatever it should be. This way you guarantee you're working with the actual "real" array, and not any of the many temporary copies your nested loops are creating.