AngularJS calculate a dynamic number of variables in braces - angularjs

Question

I want to calculate the total sum, of a dynamic number of variables within angular's brace syntax.
The for loop I would normally use would look like :
var total = 0;
for(x=0; x< objects.length; x++) {
total += objects[x].num;
}
I would like to recreate this as {{ total }} or {{total()}} and have the total update when ever one of the variables is changed.

Answer 1

Here is what you are looking for: JSFiddle
HTML
<div ng-app="myApp" ng-controller="ctrl" ng-strict-di>
{{total()}}<br/>
<input type="text" ng-model="item.num" ng-repeat="item in objects"/>
</div>
JS:
angular.module('myApp',[]).controller('ctrl',function($scope) {
angular.extend($scope,{
objects:[
{num:7},
{num:8},
{num:9}
],
total : function(){
var res = 0;
for (var i=0;i<$scope.objects.length;i++)
res+=parseInt($scope.objects[i].num);
return res;
}
});
});
UPDATE
To test if it's updating the total on object's num update play with code like this:
setInterval(function() {
$scope.objects[1].num++;
$scope.$apply();
},500); //increase num of 2nd object by 1, every half of second
To test if it's still updating when adding new objects, play with code like that:
setInterval(function() {
$scope.objects.push({num:Math.floor(Math.random()*100)});
},5000); //Add new object, with random num: value, every 5 seconds