current community

your communities

more stack exchange communities

Stack Exchange
tour help
stack overflow careers
Take the 2-minute tour ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 0 down vote favorite

I am trying my best to program an angular app. I have a problem pushing an empty array into an object.

I get an error:

TypeError: Cannot read property 'push' of undefined

I have an object called items which looks like this:

Object

 {
  "Name": "name",
  "Description": "description"
 }

I would like to push an empty array into the object that can contain another array. Something like this.

Object

 {
  "Name": "name",
  "Description": "description",
  "Related Items": {
                    Item1:{...},
                    Item2:{...},
                    ...
                   }
 }

My controller does this when it is called:

$scope.push = function () {
  $scope.item.push({"Related Items":[]});
};

I know I must be getting mixed up with something simple about the JSON Objects and Arrays, but I can't seem to find a solution.

Thankyou!

share|improve this question

3 Answers 3

up vote 2 down vote accepted

Since item is an object, you can just set the Related Items property:

$scope.item["Related Items"] = [];
$scope.item["Related Items"].push({});

However, above it looks like Related Items is actually an object with key names Item1, etc. rather than an array.

$scope.item["Related Items"] = {};
$scope.item["Related Items"].Item1 = {};
share|improve this answer
up vote 0 down vote

Javascript's push function only works when you're pushing values to an array. It won't work if you try to push to an object, instead it will try to call the key of "push" which doesn't exist. That's why you're getting the error you're getting.

Make sure that $scope.item is an array ([] or new Array), and then push to it with the value you would like.

$scope.item = [];
$scope.push = function () {
  $scope.item.push({"Related Items":[]});
};

Here's W3School's .push() method explanation.

share|improve this answer
up vote 0 down vote

The item object should be like { .... "Related Items":<"some value"> .... }

It should already have key.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.