Merge 2d arrays with same index value - php

Question

How can I merge one array inside another 2d array based on a unique value that is shared on both 2d array?
Arrays:
$arr1 = [
"First" =>[
"Name" => "John",
"Id" => 123
],
"Second" =>[
"Name" => "Peter",
"Id" => 45
]
];
$arr2 = [
"First" =>[
"Age" => 34,
"Id" => 123
],
"Second" =>[
"Age" => 24,
"Id" => 45
]
];
$n = array_merge($arr1, $arr2);
Current output when var_dump $n:
array(2) {
["First"]=>
array(2) {
["Age"]=>
int(34)
["Id"]=>
int(123)
}
["Second"]=>
array(2) {
["Age"]=>
int(24)
["Id"]=>
int(45)
}
}
Desired output:
array(2) {
["First"]=>
array(2) {
["Name"]=>
String("John")
["Age"]=>
int(34)
["Id"]=>
int(123)
}
["Second"]=>
array(2) {
["Name"]=>
String("Peter")
["Age"]=>
int(24)
["Id"]=>
int(45)
}
}
Ofcourse just by merging the two arrays wont fix my issue, but i was just wondering what approach I should take to do this.

Answer 1

Assuming this structure of your arrays, you can use array_replace_recursive.
$n = array_replace_recursive($arr1, $arr2);
Fiddle: https://3v4l.org/IPGsl
Some people can say that you can use array_merge_recursive, but no. As you have same key (Id) in both arrays, resulting array will have not the structure you expect. But in case you have different keys in both arrays - array_merge_recursive is an option too.