Edit in JSFiddle

angular.module('myapp', []);

var MyController = function($scope) {
    $scope.my_array = ['a', 'b'];
    $scope.getList = function(){
        console.log('### watch here! ###');
      
        //$scope.my_array.push(Math.random());
        return $scope.my_array;
    }
}

<div ng-app="myapp">
    <div ng-controller="MyController">
        <div ng-repeat="item in getList()">
            {{item}}
        </div>
    </div>
</div>