$scope.displayyears = [];
  $scope.Joinyear = function(display) {
    $scope.yeardisplay = display;       
    $scope.yeardisp = $scope.displayyears.push($scope.yeardisplay);
    $scope.displayyeaRSS = uniq($scope.yeardisp)
  }

它会抛出错误,如“uniq is undefined”..我们如何检查唯一性？