[angularjs] How to use a filter in a controller?

function ngController($scope,$filter){
    $scope.name = "aaaa";
    $scope.age = "32";

     $scope.result = function(){
        return $filter('lowercase')($scope.name);
    };
}

The controller method 2nd argument name should be "$filter" then only the filter functionality will work with this example. In this example i have used the "lowercase" Filter.