.html = '<script>'$("div.urun'.$productid.' #hesaplar").on("keyup change", function() {var yeniurun = document.getElementById("'.$productid.'_sepet");var value = $(this).find(":selected").val();

$html = '<div class="urun">';
$html .= '<select id="hesaplar" onchange="urunYakala(this)">'; /*** Buraya Onchange Ekledim ***/
$argumen = array(
        'meta_key' => '_price',
        'orderby' => 'meta_value_num',
        'order' => 'ASC',
        'limit'=> -1,
        'category' => array( 'denemekategorisi' ),
        'status' => 'publish',
);
$producter = wc_get_products( $argumen );
foreach ($producter as $producted) {
    $urunbaslik = $producted->get_name();
    $urunfiyat = number_format($producted->get_price(), 2, '.', '');
    $urunid = $producted->get_id();
    $urunadi = explode(" ", $urunbaslik);
    $urunayrac = str_replace( array("@", "_", "."), '', $urunadi[1]);
    $html .= '<option value="'. $urunid .'">'. $urunayrac . ' ' . $urunfiyat .'</option>';
}
$html .= '</select>';
$html .= '</div>';
$html .= '<script>function urunYakala(select) { alert(select.options[select.selectedIndex].text); }</script>'; /*** Ekstra olarak bu satırı ekledim ***/
return $html;