Don't display object's data if property doesn't exist

Question

I want to choose not to display an object's data if a property is missing from the object. I'm calling data from a REST API that removes a price_1 property from an object if the item is no longer available for purchase. I've done a little bit of research into delete but from my understanding that's only for deleting a reference to a property, not an object. I'm not sure if it's possible to entirely remove an object if a property doesn't exist, but this would be the ideal solution. I also want to know if the solution would be better suited as a custom filter.

I've tried the following:

angular.module('foldsApp.productModule', [])
    .controller('ProductsController', ['$scope', '$log', 'APIService', function ($scope, $log, APIService) {
        $scope.products = {};

        APIService.getData()
            .success(function(res) {
                $scope.products = res.results;
                for (price in $scope.products) {
                    if($scope.products[price].price_1 === 'undefined') {
                        // remove object?
                    }
                }
            })
            .error(function(data, status, headers, config) {
                $log.log('error: ' + data);
            });

    }]);

Right now, the if($scope.products[price].price_1 === 'undefined') equates to false . I'm not entirely sure why this is happening, but I assume it's because price_1 does exist on most objects in $scope.products and I'm not sure how to work with that. This is my first foray into "higher" level JavaScript, so a few things are going over my head. Any helpful resources are greatly appreciated, thanks.

HTML if that matters:

<ul>
    <li dir-paginate="product in products | itemsPerPage: 30">
        <a href="{{ product.link_1 }}"><img src="{{ product.category_product_image_placeholder_image }}" /></a>
        <br>
        {{ product.product_name_text }}
        <br>
        <strong>{{ product.price_1 | currency }}</strong>
    </li>
</ul>

Answer 1

to check for undefined specifically you should use typeof variable === 'undefined' :

so:

if(typeof $scope.products[price].price_1 === 'undefined'){
    delete $scope.products[price];
}

delete will remove properties of an object (which is what it looks like you have) and if they are not referenced anywhere else the garbage collector will pick them up.