javascript - 从 n 个项目的数组中一次显示 5 个项目，然后再次从 angularjs 中的 biginning 重复

Question

我是 angularJs 的新手，我遇到了一种情况，我必须从多个项目的数组中显示 5 个项目。那是首先显示 1-5 个项目，然后在 2-3 秒后将第 6 个项目插入顶部并从底部删除第一个项目。该数组显示为 5th on top 4th next，依此类推。所以每次用下一个项目替换顶部项目并删除底部项目。当显示最后一项时，也从第一项循环返回。也就是说，当显示最后一个项目时，下一个项目应该是第一个项目。

    $scope.activityFeedArray = function() {
    $scope.activityFeed[0] = $scope.actFeedArr[$scope.idx1];$scope.idx1=$scope.idx1+1;if($scope.idx1>=20){$scope.idx1=20-$scope.idx1};
    $scope.activityFeed[1] = $scope.actFeedArr[$scope.idx2];$scope.idx2=$scope.idx2+1;if($scope.idx2>=20){$scope.idx2=20-$scope.idx2};
    $scope.activityFeed[2] = $scope.actFeedArr[$scope.idx3];$scope.idx3=$scope.idx3+1;if($scope.idx3>=20){$scope.idx3=20-$scope.idx3};
    $scope.activityFeed[3] = $scope.actFeedArr[$scope.idx4];$scope.idx4=$scope.idx4+1;if($scope.idx4>=20){$scope.idx4=20-$scope.idx4};
    $scope.activityFeed[4] = $scope.actFeedArr[$scope.idx5];$scope.idx5=$scope.idx5+1;if($scope.idx5>=20){$scope.idx5=20-$scope.idx5};
};
 $interval(function() {$scope.activityFeedArray2();} , 1000);

Answer 1

像下面这样使用angularjs的$Interval函数:

    $interval(function() {activityFeedArray2();} , 1000);
    function activityFeedArray2() {
    $scope.activityFeed.shift();
    $scope.activityFeed.push(actFeedArr[counter]);
    counter=counter+1;
    if(counter>=actFeedArr.length) {
    counter = counter-actFeedArr.length;
    };
    };