CODE EXAMPLE FOR JAVASCRIPT

woocommerce update mini cart ajax

add_filter( 'woocommerce_add_to_cart_fragments', function($fragments) {

    ob_start();
    ?>

    <div class="cart-contents">
        <?php echo WC()->cart->get_cart_contents_count(); ?>
    </div>

    <?php $fragments['div.cart-contents'] = ob_get_clean();

    return $fragments;

} );

add_filter( 'woocommerce_add_to_cart_fragments', function($fragments) {

    ob_start();
    ?>

    <div class="header-quickcart">
        <?php woocommerce_mini_cart(); ?>
    </div>

    <?php $fragments['div.header-quickcart'] = ob_get_clean();

    return $fragments;

} );