Arrays — Indexed, Associative & Multidimensional

Indexed arrays store lists with numeric keys starting at 0. Create with array() or short syntax [].

Indexed arrays

Indexed arrays store lists with numeric keys starting at 0. Create with array() or short syntax [].

Real-life example: An indexed array is a numbered locker row — locker 0, locker 1, locker 2.

Indexed array

<?php
$courses = ["HTML", "CSS", "PHP", "MySQL"];
echo $courses[0]; // HTML
echo count($courses); // 4

$courses[] = "JavaScript"; // append
?>

Associative arrays

Associative arrays use named keys instead of numbers — perfect for user records and config settings.

Real-life example: Associative arrays are labeled drawers — "socks", "shirts", "pants" instead of drawer 1, 2, 3.

Associative array

<?php
$user = [
  "id" => 101,
  "name" => "Asha",
  "email" => "asha@example.com",
  "role" => "student"
];

echo $user["name"];
foreach ($user as $key => $val) {
  echo "$key: $val\n";
}
?>

Multidimensional arrays

Arrays can contain other arrays — useful for tables of students, products, or quiz questions.

Real-life example: A spreadsheet is a 2D array — rows and columns of data.

2D array

<?php
$students = [
  ["name" => "Asha", "score" => 88],
  ["name" => "Ravi", "score" => 92],
];

echo $students[1]["name"]; // Ravi

// Useful array functions
$nums = [3, 1, 4, 1, 5];
sort($nums);
print_r($nums);
?>