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?

• Bhojendra Rauniyar: You cannot do resulst[].count ....
• Himmators: why can't I do that?
• Bhojendra Rauniyar: is that correct way for adding property in array property?? We cannot add property to property of array...
• HTTP: There is no count property in javascript I am guessing you need the .length
• HTTP: are you trying to reset your counter value?

Answer 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;

• Himmators: Can I make it not put the cart object in, but rather create a copy of it?
• Rickard Staaf: stackoverflow.com/questions/728360/…
• Rickard Staaf: 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: 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 (javascript.crockford.com/prototypal.html)