Multidimensional Arrays

Nested Arrays

Multidimensional arrays are arrays that contain arrays. They are common when representing lists of records (like DB rows) or nested JSON payloads.

<?php
$users = [
  ['id' => 1, 'name' => 'Ozan'],
  ['id' => 2, 'name' => 'Ayse'],
];

echo $users[1]['name']; // Ayse

Iterating a List of Records

This pattern appears constantly in backend code: you fetch rows and loop through them.

<?php
foreach ($users as $user) {
  echo $user['id'] . ' - ' . $user['name'] . PHP_EOL;
}

Nested Key Access Safely

Deep access can cause undefined index warnings. Use ?? at each level or normalize data before use.

<?php
$payload = [
  'user' => [
    'profile' => [
      'city' => 'Ankara'
    ]
  ]
];

$city = $payload['user']['profile']['city'] ?? 'Unknown';
echo $city;

Building a Data Structure

Sometimes you build nested structures for JSON APIs.

<?php
$response = [
  'ok' => true,
  'data' => [
    'items' => [
      ['id' => 1, 'title' => 'PHP Intro'],
      ['id' => 2, 'title' => 'Arrays'],
    ],
    'pagination' => [
      'page' => 1,
      'limit' => 20,
    ],
  ],
];

echo json_encode($response);

Production Tip

Nested arrays are flexible but can become fragile. Keep structures consistent and validate inputs. For complex nested payloads, consider DTO objects and dedicated validation.