php function hello name return Hello name function goodbye name return

<?php
    function hello($name)
    {
        return “Hello $name!\n”;
    }
    
    function goodbye($name)
    {
        return “Goodbye $name!\n”;
    }
    function age($birthday) 
    {
        $ts = strtotime($birthday);
            if($ts === -1) {
                return “Unknown”;
            } else {
                $diff = time() - $ts;
                return floor($diff/(24*60*60*365));
            }
    }
    
    $name = “george”;
    $bday = “10 Oct 1973”;

echo hello($name);
echo “You are “.age($bday).” years old.\n”;
echo goodbye($name);
?>