How to count data from an array based on another array's value in PHP?

I have an array that contains data of incoming mail, looks something like this:

$incomingMail = [
   0 => [
      'title' => 'Title 1',
      'areaCode' => 101
   ],
   1 => [
      'title' => 'Title 2',
      'areaCode' => 101
   ],
   2 => [
      'title' => 'Title 3',
      'areaCode' => 102
   ]
];

And another array containing area name and code, the array looks like this:

$areaArr = [
   0 => [
      'name' => 'Area 1',
      'code' => 101
   ],
   1 => [
      'name' => 'Area 2',
      'code' => 102
   ],
   2 => [
      'name' => 'Area 3',
      'code' => 103
   ],
   3 => [
      'name' => 'Area 4',
      'code' => 104
   ]
];

I want to create an array that contains the count of incomingMail array based on areaArr‘s code, it will kind of looks like this:

$areaWithMailCount = [
   0 => [
      'areaName' => 'Area 1',
      'areaCode' => 101,
      'mailCount' => 2
   ],
   1 => [
      'areaName' => 'Area 2',
      'areaCode' => 102,
      'mailCount' => 1
   ],
   2 => [
      'areaName' => 'Area 3',
      'areaCode' => 103,
      'mailCount' => 0
   ],
   3 => [
      'areaName' => 'Area 4',
      'areaCode' => 104,
      'mailCount' => 0
   ]
];

I have tried to loop those arrays and add the condition based on area code but the result isn’t quite what I wanted, the code looks something like this:

$areaWithMailCount = [];

foreach($areaArr as $area) {
   foreach($incomingMail as $mail) {
      if($mail['areaCode'] == $area['code']) {
         $areaWithMailCount[] = [
            'areaName' => $area['name'],
            'areaCode' => $area['code'],
            'mailCount' => count($mail)
         ];
      }
   }
}

The result from above code is like this:

[
  0 => [
    "areaName" => "Area 1"
    "areaCode" => 101
    "mailCount" => 2
  ],
  1 => [
    "areaName" => "Area 1"
    "areaCode" => 101
    "mailCount" => 2
  ],
  2 => [
    "areaName" => "Area 2"
    "areaCode" => 102
    "mailCount" => 2
  ]
];

Any ideas how to achieve that? Thanks in advance.

>Solution :

You can achieve the desired result using a nested loop to iterate over each element of $areaArr, and for each element, loop through $incomingMail to count the number of mails with the same area code. Here’s how you can do it:

$areaWithMailCount = [];

foreach ($areaArr as $area) {
    $mailCount = 0;
    foreach ($incomingMail as $mail) {
        if ($mail['areaCode'] == $area['code']) {
            $mailCount++;
        }
    }
    $areaWithMailCount[] = [
        'areaName' => $area['name'],
        'areaCode' => $area['code'],
        'mailCount' => $mailCount
    ];
}

In this code, we first initialize the mail count to 0. We then loop through $incomingMail and check if the area code matches that of the current $area. If it does, we increment the mail count. Finally, we add a new element to $areaWithMailCount with the area name, code, and mail count.

This should give you the desired result in $areaWithMailCount.