functions.php

<?php

// Define functions
function welcomePerson($person_name, $person_age = 25)
{
    echo "Welcome $person_name, your age is $person_age";
    echo "<br>";
}

// Calling functions
welcomePerson("Hani", 27);
welcomePerson("Amin", 24);
welcomePerson("Mohammed");

$my_name = 'Ali';
welcomePerson($my_name);

function sum($x, $y) {
    return $x + $y;
}

echo sum(6, 4);
echo '<br>';
echo sum(3, 4);
echo '<br>';


// Built-in functions
$arr = ['BMW', 'KIA', 'Audi', 'Mazda'];
echo count($arr);

echo '<br>';

$str = 'Ahmed';
echo strlen($str);