Javascript Count 价格和数量

Question

Cart.PHP

   <div class="shopping-cart">
            <section class="container content-section">
                <h1>CART</h1>
        

                <?php

                $total = 0;
                    if (isset($_SESSION['cart'])){
                        $product_id = array_column($_SESSION['cart'], 'product_id');

                        $result = $db->getData();
                        while ($row = mysqli_fetch_assoc($result)){
                            foreach ($product_id as $id){
                                if ($row['id'] == $id){
                                    cartElement($row['product_image'], $row['product_name'],$row['product_price'], $row['id']);
                                    $total = $total + (int)$row['product_price'];
                                }
                            }
                        }
                    }else{
                        echo "<h5>Cart is Empty</h5>";
                    }

                ?>
                    <div class="cart-total">
        <strong class="cart-total-title">Total</strong>
        <span class="cart-total-price">$0</span>
    </div>
    <button class="btn btn-primary btn-purchase" type="button">CONFIRM ORDER</button>

                </section>
                </div>

component.php

function cartElement($productimg, $productname, $productprice, $productid){
    $element = "
    
    <form action=\"cart.php?action=remove&id=$productid\" method=\"post\" class=\"cart-items\">
 
    <div class=\"cart-row\">
        <span class=\"cart-item cart-header cart-column\">$productname</span>
        <span class=\"cart-price cart-header cart-column\">RM$productprice</span>
        <span class=\"cart-quantity cart-header cart-column\"><input type=\"number\" value=\"1\" min=\"1\"></span>
        <button type=\"submit\" class=\"btn btn-danger mx-2\" name=\"remove\">Remove</button>
    </div>
    <div class=\"cart-items\">
    </div>
                </form>
    
    ";
    echo  $element;
}

Hello everyone, I would like to count the quantity and the price of it which is the total. Is it possible to do with javascript or php and how? I have tried several ways to implement the function in javascript however none of my effort works.Thank you for helping me.

Answer 1

i don't know how the cart stores data on the session, but doing in the following way will make it easy.

$cartProducts = array_keys($_SESSION['cart']);

get product details from the DB something like:- where product_id IN(implode(',',$cartProducts))"

loop through the products got from the DB

$total = 0;
while ($row = mysqli_fetch_assoc($result)){
 $subtotal = $row['price'] * ($_SESSION['cart'][$row['id']]['quantity']);
 $total += $subtotal;
// now you got product detail, quantity, price
// print the html formatted information here 
}

at the end print the $total

if you change the quantity - then update the session cart, and repeat the above.

Note:- it is just an example, you need to add validations, fomat/secure sql etc