使用拼接问题删除数组中的数组

Question

I have and array added_collections and current state is:

    added_collections
(2) [Array(2), Array(1)]
0: Array(2)
0: []
1: [{…}]
length: 2
[[Prototype]]: Array(0)
1: [Array(10)]
length: 2

I need to remove an product from collection so I write:

added_collections[0][1].splice(0, 1);

so the result I expect to get is:

added_collections
(2) [Array(2), Array(1)]
0: Array(2)
0: []
1: []
length: 2
[[Prototype]]: Array(0)
1: [Array(10)]
length: 2
[[Prototype]]: Array(0)

but instead that I get:

(2) [Array(2), Array(1)]
0: Array(0)
length: 0
[[Prototype]]: Array(0)
1: [Array(10)]
length: 2

Why its two empty arrays are merged?

When I follow steps in browser console everything is fine but when I run the same code to execute its not the same results and seems that 2 empty arrays missing

UPDATE: this is the full code of added_collection[0]:

'[[[],[{"id":32620843270280,"product_id":4632299831432,"title":"3 / red","price":"249.00","sku":"DM-03-red-3","position":1,"inventory_policy":"deny","compare_at_price":"0.00","fulfillment_service":"manual"}]]]'

and I run js code:

let coll_no = 0;
    let page_no = 1;
    let product_no = 0;

    added_collections[coll_no][page_no].splice(product_no, 1);

Answer 1

Works fine for me

 const collection = [ [ [], [{ "id": 32620843270280, "product_id": 4632299831432, "title": "3 / red", "price": "249.00", "sku": "DM-03-red-3", "position": 1, "inventory_policy": "deny", "compare_at_price": "0.00", "fulfillment_service": "manual" }] ] ] collection[0][1].splice(0, 1) console.log(collection)