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# Method name: updateLineItemsQuantity(_id: string, lineItems: Array<LineItemQuantityUpdate>)

# Method package: wixEcomBackend

# Method menu location: wixEcomBackend --> cart --> updateLineItemsQuantity

# Method Link: https://dev.wix.com/docs/velo/apis/wix-ecom-backend/cart/update-line-items-quantity.md

# Method Description:

Updates the quantity of 1 or more line items in a cart.


The `updateLineItemsQuantity()` function returns a Promise that resolves when the quantities of the specified cart's line items are updated.

This endpoint is only for updating the quantity of line items. To entirely remove a line item from the cart, use [`removeLineItems()`](#removelineitems). To add a new line item to the cart, use [`addToCart()`](#addtocart).

This endpoint checks the amount of stock remaining for this line item. If the specified `quantity` is greater than the remaining stock, then the `quantity` returned in the response is the total amount of remaining stock.

> **Note:** After a cart is updated, call [Refresh Cart](https://dev.wix.com/docs/velo/apis/wix-ecom-frontend/refresh-cart.md) to update the cart's UI elements and trigger the Cart Updated event.



# Method Code Examples:

*** Note: do not assume any prop names or enum values other than the ones in the example.

## Update the quantity of a cart's line items 

```javascript
/*****************************************
 * Backend code - my-backend-file.web.js *
 *****************************************/

import { Permissions, webMethod } from 'wix-web-module';
import { cart } from 'wix-ecom-backend';

export const myUpdateLineItemsQuantityFunction = webMethod(Permissions.Anyone, async (cartId, lineItems) => {
  try {
    const updatedCart = await cart.updateLineItemsQuantity(cartId, lineItems);
    console.log('Success! Line item quantities updated:', updatedCart);
    return updatedCart;
  } catch (error) {
    console.error(error);
    // Handle the error
  }
});

/*************
 * Page code *
 *************/

import wixEcomFrontend from 'wix-ecom-frontend';
import { myUpdateLineItemsQuantityFunction } from 'backend/my-backend-file.web';

// Sample cartId:
const cartId = 'b79fd177-ec98-4245-b9f6-f09e7afa9d04';

// Sample lineItems array:
const lineItems = [
  {
    "_id": '00000000-0000-0000-0000-000000000001',
    "quantity": 2
  },
  {
    "_id": '00000000-0000-0000-0000-000000000002',
    "quantity": 3
  }
]

const updatedCart = await myUpdateLineItemsQuantityFunction(cartId, lineItems);

// Refresh the cart after adding item.
await wixEcomFrontend.refreshCart();

// Navigate to the cart page.
await wixEcomFrontend.navigateToCartPage();

/* Updated cart:
 *
 * {
 *   "_id": "b79fd177-ec98-4245-b9f6-f09e7afa9d04",
 *   "lineItems": [
 *     {
 *       "_id": "00000000-0000-0000-0000-000000000001",
 *       "quantity": 2,
 *       "catalogReference": {
 *         "catalogItemId": "df19c1f7-07d8-a265-42f8-e8dfa824cc6e",
 *         "appId": "215238eb-22a5-4c36-9e7b-e7c08025e04e",
 *         "options": {
 *           "variantId": "e62fee23-7878-437a-bf0e-292f17d11cb5"
 *         }
 *       },
 *       "productName": {
 *         "original": "Shoe",
 *         "translated": "Shoe"
 *       },
 *       "url": "https://example.wixsite.com",
 *       "price": {
 *         "amount": "85",
 *         "convertedAmount": "85",
 *         "formattedAmount": "€85.00",
 *         "formattedConvertedAmount": "€85.00"
 *       },
 *       "fullPrice": {
 *         "amount": "85",
 *         "convertedAmount": "85",
 *         "formattedAmount": "€85.00",
 *         "formattedConvertedAmount": "€85.00"
 *       },
 *       "priceBeforeDiscounts": {
 *         "amount": "85",
 *         "convertedAmount": "85",
 *         "formattedAmount": "€85.00",
 *         "formattedConvertedAmount": "€85.00"
 *       },
 *       "descriptionLines": [
 *         {
 *           "name": {
 *             "original": "Color",
 *             "translated": "Color"
 *           },
 *           "colorInfo": {
 *             "original": "Black",
 *             "translated": "Black",
 *             "code": "#000"
 *           },
 *           "lineType": "UNRECOGNISED"
 *         }
 *       ],
 *       "image": "wix:image://v1/3c76e2_bf235c38610f4d2a905db71095b351cf~mv2.jpg#originWidth=1000&originHeight=1000",
 *       "availability": {
 *         "status": "AVAILABLE",
 *         "quantityAvailable": 30
 *       },
 *       "physicalProperties": {
 *         "sku": "364215376135191",
 *         "shippable": true
 *       },
 *       "couponScopes": [
 *         {
 *           "namespace": "stores",
 *           "group": {
 *             "name": "collection",
 *             "entityId": "00000000-000000-000000-000000000001"
 *           }
 *         },
 *         {
 *           "namespace": "stores",
 *           "group": {
 *             "name": "product",
 *             "entityId": "df19c1f7-07d8-a265-42f8-e8dfa824cc6e"
 *           }
 *         }
 *       ],
 *       "itemType": {
 *         "preset": "PHYSICAL"
 *       },
 *       "paymentOption": "FULL_PAYMENT_ONLINE"
 *     },
 *     {
 *       "_id": "00000000-0000-0000-0000-000000000002",
 *       "quantity": 3,
 *       "catalogReference": {
 *         "catalogItemId": "1a2d7e83-4bef-31d5-09e1-3326ee271c09",
 *         "appId": "215238eb-22a5-4c36-9e7b-e7c08025e04e",
 *         "options": {
 *           "variantId": "132b84e8-aab8-47a1-a1f6-2c47557b64a4"
 *         }
 *       },
 *       "productName": {
 *         "original": "Watch",
 *         "translated": "Watch"
 *       },
 *       "url": "https://example.wixsite.com",
 *       "price": {
 *         "amount": "30",
 *         "convertedAmount": "30",
 *         "formattedAmount": "€30.00",
 *         "formattedConvertedAmount": "€30.00"
 *       },
 *       "fullPrice": {
 *         "amount": "30",
 *         "convertedAmount": "30",
 *         "formattedAmount": "€30.00",
 *         "formattedConvertedAmount": "€30.00"
 *       },
 *       "priceBeforeDiscounts": {
 *         "amount": "30",
 *         "convertedAmount": "30",
 *         "formattedAmount": "€30.00",
 *         "formattedConvertedAmount": "€30.00"
 *       },
 *       "descriptionLines": [
 *         {
 *           "name": {
 *             "original": "Size",
 *             "translated": "Size"
 *           },
 *           "plainText": {
 *             "original": "Medium",
 *             "translated": "Medium"
 *           },
 *           "lineType": "UNRECOGNISED"
 *         },
 *         {
 *           "name": {
 *             "original": "Color",
 *             "translated": "Color"
 *           },
 *           "colorInfo": {
 *             "original": "Grey",
 *             "translated": "Grey",
 *             "code": "rgb(128, 128, 128)"
 *           },
 *           "lineType": "UNRECOGNISED"
 *         }
 *       ],
 *       "image": "wix:image://v1/3c76e2_8891bbe3372a428aac976ac59aa0ac74~mv2.jpg#originWidth=1000&originHeight=1000",
 *       "availability": {
 *         "status": "AVAILABLE"
 *       },
 *       "physicalProperties": {
 *         "sku": "217537123517253",
 *         "shippable": true
 *       },
 *       "couponScopes": [
 *         {
 *           "namespace": "stores",
 *           "group": {
 *             "name": "collection",
 *             "entityId": "00000000-000000-000000-000000000001"
 *           }
 *         },
 *         {
 *           "namespace": "stores",
 *           "group": {
 *             "name": "product",
 *             "entityId": "1a2d7e83-4bef-31d5-09e1-3326ee271c09"
 *           }
 *         }
 *       ],
 *       "itemType": {
 *         "preset": "PHYSICAL"
 *       },
 *       "paymentOption": "FULL_PAYMENT_ONLINE"
 *     }
 *   ],
 *   "buyerInfo": {
 *     "visitorId": "4c7ce95c-9fb3-417d-9f02-b41e82b841f7"
 *   },
 *   "currency": "EUR",
 *   "conversionCurrency": "EUR",
 *   "buyerLanguage": "en",
 *   "siteLanguage": "en",
 *   "taxIncludedInPrices": false,
 *   "weightUnit": "KG",
 *   "subtotal": {
 *     "amount": "260",
 *     "convertedAmount": "260",
 *     "formattedAmount": "€260.00",
 *     "formattedConvertedAmount": "€260.00"
 *   },
 *   "appliedDiscounts": [],
 *   "inSync": false,
 *   "_createdDate": "2022-06-22T11:32:29.601Z",
 *   "_updatedDate": "2022-06-22T11:36:48.831Z"
 * }
 *
 */
```

---