How to update cart item quantitty with ajax in laravel?

I want to increment/decrement cart quantity by clicking the button. See this image preview image

This cart row is shown by forcach loop. First row is working perfectly. The problem is, when I click on the seceond/last row, I get only first row value. I don’t know how to solve that. Here is view code

    @foreach ($carts as $cart)
                            <input type="hidden" name="cart_id" class="id" value="{{ $cart->id }}">
                            <tr class="woocommerce-cart-form__cart-item cart_item">
                                <td class="product-remove">
                                    <a href="#" class="remove" onclick="removeCart({{ $cart->id }})"
                                        aria-label="Remove this item">
                                        <span class="lnr lnr-cross-circle"></span>
                                    </a>
                                </td>

                                <td class="product-thumbnail">
                                    <a href="">
                                        <img src="{{ asset('/storage/items/food/' . $cart->FoodItem->image) }}"
                                            class="attachment-shop_thumbnail size-shop_thumbnail wp-post-image" alt="" /
                                            height="60" width="80">
                                    </a>
                                </td>

                                <td class="product-name" data-title="Product">
                                    <a href="shop-single.html">{{ $cart->FoodItem->name }}</a>
                                </td>

                                <td class="product-price" data-title="Price">
                                    <span class="woocommerce-Price-amount amount"><span
                                            class="woocommerce-Price-currencySymbol">$</span>{{ $cart->price }}</span>
                                </td>
                                <td class="product-quantity" data-title="Quantity">
                                    <div class="quantity">
                                        <input type="number" class="input-text qty text input-quantity "
                                            class="quantity" step="1" min="0" name="quantity[]"
                                            value="{{ $cart->quantity }}" title="Qty" size="4">
                                        <div class="icon">
                                            <a href="#" class="number-button  plus">+</a>
                                            <a href="#" class="number-button minus">-</a>
                                        </div>
                                    </div>
                                </td>
                                <td class="product-subtotal" data-title="Total">
                                    <span class="woocommerce-Price-amount amount"><span
                                            class="woocommerce-Price-currencySymbol">$</span> <span
                                            class="sum">{{ $cart->total_price }}</span></span>
                                </td>
                            </tr>
                        @endforeach

Here is ajax code

    $(document).on('click', '.qty', function(e) {
        e.preventDefault();

        var quantity = $('.input-quantity').val();  
        var id = $('.id').val();

          $.ajax({
            url: "url",
            method: "POST",
            dataType: "json",
            data: {
                _token: "{{ csrf_token() }}",

                quantity: quantity,
                id: id,
            },

Here my controller code

   $cart = Cart::findOrFail($id);
    $cart->update([
        'quantity'    => $request->quantity,
        'total_price' => $cart['price'] * $request->quantity,

    ]);

Can anyone tell me way how to solve that problem?

Answer

Here is the problem:

    var quantity = $('.input-quantity').val();  
    var id = $('.id').val();

jQuery fetch’s the value of the first item with class .input-quantity every time because you’ve used this:

$('.input-quantity') 

so you should tell it to pass the value for related item to the clicked item:

$(document).on('click', '.qty', function(e) {
    e.preventDefault();

    // $(this) mentions the clicked element (target)
    var quantity = $(this).val();  // trasnlate: pass the value of the clicked  (target) element
    ....

}

Also I didn’t find you’ve set id anywhere! so you can set as as an data-attribute like this:

<input data-id={{ $cart->id }} type="number" 
       class="input-text qty text input-quantity "
       step="1" min="0" name="quantity[]"
       value="{{ $cart->quantity }}" title="Qty" size="4">

then you can use this code:

$(document).on('click', '.qty', function(e) {
    e.preventDefault();

    // $(this) mentions the clicked element (target)
    var quantity = $(this).val();  // trasnlate: pass the value of the clicked  (target) element
    var id = $(this).attr("data-id");
    ....

}

You must consider that you’ve used class twice for an element:

class="input-text qty text input-quantity "  class="quantity"

that is absolutely wrong