Using variables to build JS Object

Question

I want to create an object that has some keys which come from a variable parameter. Let's say for example that prod_id below is a variable containing some value... I want to create an object which has an attribute with key of that 'prod_id' and value of 1. However this does not work? Is this possible to achieve? if so, how? thanks a heaps

var cart_obj;
  cart_obj = {
  prod_id : 1
};
localStorage.setItem("cart", JSON.stringify(cart_obj));

possible duplicate of [How do I add a property to a Javascript Object using a variable as the name?](http://stackoverflow.com/questions/695050/how-do-i-add-a-property-to-a-javascript-object-using-a-variable-as-the-name) — T.J. Crowder, Apr 17 '14 at 17:29
...and searching gives us [this previous question and its answers](http://stackoverflow.com/questions/695050/how-do-i-add-a-property-to-a-javascript-object-using-a-variable-as-the-name). Amazing, what a search can do. — T.J. Crowder, Apr 17 '14 at 17:29

score 2 · Accepted Answer · answered Apr 17 '14 at 17:26

2

You can't do it with a simple object literal. You can do this however:

var cart_obj = {};
cart_obj[prod_id] = 1;

JavaScript object literal syntax makes no provisions for expressions on the left side of a property declaration stanza.

answered Apr 17 '14 at 17:26

Pointy

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score 1 · Answer 2 · answered Apr 17 '14 at 17:28

1

var cart_obj = {};
cart_obj.prod_id = 1;

or

var cart_obj = {};
cart_obj[prod_id] = 1;

answered Apr 17 '14 at 17:28

bobthedeveloper

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Using variables to build JS Object

2 Answers2