Arrays

Arrays are PHP's way of storing multiple values in a single variable. Think of them as a numbered list or a labeled filing cabinet. In PHP, arrays are incredibly flexible — they can grow and shrink dynamically, and they can hold any mix of types.

Indexed Arrays

An indexed array uses numeric keys, starting at 0. It's the simplest array type — just a list of values. You can create one with array() or the shorthand [].

<?php
$colors = ["Red", "Green", "Blue"];

echo $colors[0];  // Red
echo $colors[1];  // Green
echo $colors[2];  // Blue

// Add a new element
$colors[] = "Yellow";
?>
    

Associative Arrays

Associative arrays use named keys instead of numbers. They're like dictionaries — you look up a word (key) and get the definition (value). This is where PHP arrays really shine.

<?php
$student = [
  "name" => "Bilal",
  "age" => 25,
  "course" => "Web Development"
];

echo $student["name"];    // Bilal
echo $student["course"];  // Web Development
?>
    

Multidimensional Arrays

An array inside an array. This is how you represent tables, grids, or complex data structures. Each element in the outer array is itself an array.

<?php
$matrix = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

echo $matrix[0][0];  // 1
echo $matrix[1][2];  // 6

$users = [
  ["name" => "Ali", "email" => "ali@test.com"],
  ["name" => "Sara", "email" => "sara@test.com"]
];

echo $users[1]["email"];  // sara@test.com
?>
    

Useful Array Functions

PHP ships with dozens of array functions. These are the ones I use most:

<?php
$items = ["Pen", "Book", "Eraser"];

echo count($items);       // 3 — number of elements
sort($items);             // sorts alphabetically
print_r($items);          // prints array structure

array_push($items, "Ruler");  // adds element at the end
array_pop($items);            // removes last element
array_shift($items);          // removes first element
$reversed = array_reverse($items);

echo in_array("Book", $items);  // 1 (true) — checks if value exists
?>