How come variable get's assigned to another array?

Question

I'm trying to walk through a sorted array and count the duplicates to create a new summary-array.

        for (var i = 0; i < newCart.length; i++) {
        //if new item.
        console.log(JSON.stringify(newCart[i - 1]))
        if ( JSON.stringify(newCart[i - 1]) !==  JSON.stringify(newCart[i])) {
            //add to new displayed items in cart
            results.push(newCart[i]);
            results[results.length - 1].count = 1
        }else{
            console.log('second')
            //add one to the count.
            results[results.length - 1].count++;
        }
    }

When I'm looping through this with three items, I get the following output:

undefined
{"id":1,"name":"Skateboard","price":1299,"currency":"SEK","image":"/static/img/products/1.jpg","thumbnail":"/static/img/products/1-t.jpg","description":"This board is the boss!","count":1} main.js:47
{"id":1,"name":"Skateboard","price":1299,"currency":"SEK","image":"/static/img/products/1.jpg","thumbnail":"/static/img/products/1-t.jpg","description":"This board is the boss!","count":1}

How is it possible that the count variable ends up in the newCart-array?

is that correct way for adding property in array property?? We cannot add property to property of array... — Bhojendra Rauniyar, Sep 08 '14 at 09:43
Okay... I'm not sure I follow, what should I do instead? And why does it end up in the newCart array? — Himmators, Sep 08 '14 at 09:45
There is no `count` property in javascript I am guessing you need the `.length` — HTTP, Sep 08 '14 at 09:45
@HTTP Um, yeah! OP might be trying to use that, but incrementing with, it's confusing to me... and I think OP needs to set a variable and then increment in there.. — Bhojendra Rauniyar, Sep 08 '14 at 09:46
@HTTP, no I try to increase the count by one for each idenctical item. — Himmators, Sep 08 '14 at 09:53

score 1 · Answer 1 · edited Sep 08 '14 at 09:48

1

Because when you do results.push(newCart[i]) it actually puts your cart object into the array, and then you access that newCart[i] object and add count to that newCart[i] object with results[results.length-1].count=1;

edited Sep 08 '14 at 09:48

Himmators

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answered Sep 08 '14 at 09:47

Rickard Staaf

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Can I make it not put the cart object in, but rather create a copy of it? – Himmators Sep 08 '14 at 09:53
http://stackoverflow.com/questions/728360/most-elegant-way-to-clone-a-javascript-object – Rickard Staaf Sep 08 '14 at 10:06
Could not let this go, since I know I have done similar things in the past. In the question linked above they are actually trying to clone an object without the values. To do what you want to do a simple: `results.push(Object.create(newCart[i]))` – Rickard Staaf Sep 08 '14 at 10:51
It only works in IE9 and newer though (and Chrome, and FF and Safari of course). But it is possible to implement for all brosers, see here for that if neccessary (http://javascript.crockford.com/prototypal.html) – Rickard Staaf Sep 08 '14 at 10:58

How come variable get's assigned to another array?

1 Answers1