<?php
$numbers = [1, 2, 3, 4, 5];

// Double each number in the array
$doubledNumbers = array_map(function($number) {
    return $number * 2;
}, $numbers);

echo "Doubled Numbers:
";
print_r($doubledNumbers);

$names = ['alice', 'bob', 'charlie'];

// Capitalize the first letter of each name
$capitalizedNames = array_map('ucfirst', $names);

echo "
Capitalized Names:
";
print_r($capitalizedNames);

// Extracting a specific column from an array of associative arrays
$users = [
    ['id' => 1, 'name' => 'Alice'],
    ['id' => 2, 'name' => 'Bob'],
    ['id' => 3, 'name' => 'Charlie'],
];

$userNames = array_map(function($user) {
    return $user['name'];
}, $users);

echo "
User Names (extracted column):
";
print_r($userNames);