PHP soru

function genelayar() {
$title = "Title";
$footer = "Footer";
}

<?php gelenayar() ?>
<?=$title?>

function genelayar() {
$data['title'] = "Title";
$data['footer'] = "Footer";
return $data;
}

<?php
$gel = genelayar();
echo $gel['title'];
?>

function genelayar() {
    global $title;

    $title = 'a';
    $footer = 'b';
}

echo $title; // null
echo $footer; // null

genelayar();

echo $title; // a
echo $footer; // null