angularjs - Empty an array before push -

i took project using angularjs. there filtering system. actually, click on category add category list. industries got category shown. note click on selected category remove category.

i click replace filtering category each click not add category. how should modify code:

$scope.changercategorie = function(category , name ){     if( jquery.inarray(category, $scope.selected ) !== -1)     {        angular.foreach($scope.selected , function(obj,index){              if( category == obj ){                 $scope.selected.splice(index,1);                 $scope.selected_name.splice(index,1);             }        });      }else{         $scope.selected.push(category);         $scope.selected_name.push(name);     }     $scope.selected_filter = $scope.selected.join(', ');  } 

i tried doesn't work

$scope.changercategorie = function(category , name ){        $scope.selected = 0;       $scope.selected_name = 0;        $scope.selected = category;       $scope.selected_name = name;        $scope.selected_filter = $scope.selected.join(', ');  } 

and get

$scope.selected.join not function 

if remove line related selected.join got error after 2 clicks:

duplicates in repeater not allowed. use 'track by' expression specify unique keys. repeater: tags in selected_name, duplicate key: string:l 

how should do?

i believe preferred way empty array in javascript set length 0: $scope.selected.length = 0.

the reason getting error on join() setting $scope.selected directly category, not array. fix that: $scope.selected = [category];

of course, need 1 of these methods. either empty followed push, or direct assignment. if planning on getting rid of multiple filter feature, may better in long run store category rather array.