Иван Козлов

if (get_post_meta(get_the_ID(), '_stock_status', true) == 'outofstock') {
  echo '<div class="outofstock">Нет в наличии</div>';
} else {
  echo '<div class="stock">В наличии</div>';
}

remove_action( 'woocommerce_shop_loop_item_title', 'woocommerce_template_loop_product_title', 10 );
add_action( 'woocommerce_shop_loop_item_title', 'custom_woocommerce_template_loop_product_title', 10 );
function custom_woocommerce_template_loop_product_title() {
echo '<h3 class="myclass">' . get_the_title() . '</h3>';
}