In JS, the plus operator will concatenate instead of add values if at least one is a string. Since your quantity (and price) have quotation marks around them, they are strings instead of numbers, so that's causing this issue.
Anyway, you can resolve this either by making sure your quantities are passed in as numbers to start, or by adjusting the script to force any number-like strings to numbers. Something like this should work:
function (){
var prods = {{DL – ecommerce.purchase.products}};
var i;
var sum = 0;
if (!prods) { return; }
for (i = 0; i < prods.length; i++) { sum +=parseInt((prods[i].quantity)) } return sum; }

I've tried the first script (total quanity) and have implemented the following Custom JS:

function (){
var prods = {{DL – ecommerce.purchase.products}};
var i;
var sum = 0;
if (!prods) { return; }
for (i = 0; i < prods.length; i++) { sum +=(prods[i].quantity) } return sum; }

However, it doesnt really sum, but it concatenates as a string to '011', while my endresult should be '2' (quantity 1+1)

Data Layer Variable array
[
{
id: '1',
name: 'Test product 1',
price: '4.54',
quantity: '1'
},
{
id: '2',
name: 'Test product 2',
price: '20.25',
quantity: '1'
}
]

How can I change this? Thanks for your help!

I think you'd just need to add in a second conditional statement to exclude the product ID. Something like this should work:
function(){
var prods = {{DL - ecommerce.purchase.products}};
var i;
var sum = 0;
if (!prods) { return; }
for (i = 0; i < prods.length; i++) { if (prods[i].id!="1001") {
sum +=(prods[i].quantity)
} }
return sum;
}

How would I filter our a specific product ID from the ecommerce datalayer and count the quantity for all other products?

e.g. if product id = 1001 exclude from count of product quantity?

Thanks!

Hi John! I checked out the new data layer format and the “price” and “quantity” fields haven’t changed from the GTM format. So I’m not yet sure what the issue is, since it looks like it should work. Just to confirm, you changed the DL variable from ecommerce.purchase.products to ecommerce.items, right? And, do the other scripts from the post work? If so, can you please check if your data layer is using a non-standard format or missing the price/quantity fields in the items array?a

I'm struggling with the "total price" script. When using the updated Google ecommerce framework (https://developers.google.com/tag-manager/ecommerce-appweb) which uses the term "items" in place of "products", the DLV keep showing as "undefined" when using this script:

function (){
var prods = {{ecommerce.items}};
var i;
var sum = 0;
if (!prods) { return; }
for (i = 0; i < prods.length; i++) {
sum +=parseFloat(prods[i].price*prods[i].quantity)
}
return sum;
}

Any advice?

I think the replace method probably does what you want. For example, this would remove all the quotation marks:

function(){
 return JSON.stringify({{JS – Product Attributes}}).replace(/"/g,"");
}

This is just a JavaScript question, so you can check out some JS tutorials online and then change your output exactly the way you want.

sorry, not delete these [ ] symbols 🙂

How can i delete the next simbols in Attributtes names e.g "categoria"-"producto"- "precio" - "cantidad":
" , { , and [
and how can i separate products with "|" symbol in the collected string with your function:
Subset Atributos: [{"categoria":"Sweaters","producto":"Hoodie con bolsillo canguro","precio":75,"cantidad":1,"talla":"xl"},{"categoria":"Cap","producto":"Gorra de pana orgánica y PIÑATEX","precio":53,"cantidad":1}]

to get something like this:

Subset Atributos: [categoria:"Sweaters", producto:"Hoodie con bolsillo canguro", precio:75, cantidad:1, talla:"xl" | categoria:"Cap", producto:"Gorra de pana orgánica y PIÑATEX", precio:53, cantidad:1]