Map associative array to another array php

Question

I have an associative array of the states of some country, and the states names are the keys:

array:13 [
  "Ontario" => null
  "Manitoba" => null
  "New Brunswick" => null
  "Yukon" => null
  "Saskatchewan" => null
  "Prince Edward Island" => null
  "Alberta" => null
  "Quebec" => null
  "Nova Scotia" => null
  "British Columbia" => null
  "Nunavut" => null
  "Newfoundland and Labrador" => null
  "Northwest Territories" => null
] 

And I have anothe associative array that contains all states that have values:

array:8 [
  "Alberta" => 17
  "Cairo" => 1
  "Calgary" => 1
  "ddd" => 4
  "gfdxf" => 1
  "New Cairo" => 1
  "Ontario" => 1
  "secret" => 30
] 

Now I need to map the second array to the first one so that the result would be:

array:13 [
  "Ontario" => 1
  "Manitoba" => 0
  "New Brunswick" => 0
  "Yukon" => 0
  "Saskatchewan" => 0
  "Prince Edward Island" => 0
  "Alberta" => 17
  "Quebec" => 0
  "Nova Scotia" => 0
  "British Columbia" => 0
  "Nunavut" => 0
  "Newfoundland and Labrador" => 0
  "Northwest Territories" => 0
] 

I created a nested loop and it works fine, but the code is very ugly, now is there a more efficent way to do it?

My code:

foreach ($all_states as $state_x => $value_x) {

    foreach ($country_states as $state_y => &$value_y) {

        if (strtolower($state_x) == strtolower($state_y)) {

            $value_y = $value_x;
        } elseif ($value_y == NULL) {

            $value_y = 0;
        }
    }
}