Better method for checking between two items in array

Question

Better method for checking between two items in array

I have an array like so:

var data = [
    {
        "title" : "Title 1",
        "slideText" : "",
        "startTime" : 0
    },
    {
        "title" : "Title 2",
        "slideText" : "",
        "startTime" : 60
    },
    {
        "title" : "Title 3",
        "slideText" : "",
        "startTime" : 120
    }
];

I have a seeked event listener on an HTML5 video. When a user seeks, I need to check where they are at and determine which index in the array they're on. For example, they seek to 72 seconds, they would be on array[1]

Right now I have this:

player.addEventListener("seeked", function(event)
{
    currentTime = player.currentTime;
    angular.forEach($scope.data, function(value, key)
    {
        if (currentTime >= $scope.data[key].startTime && currentTime <= $scope.data[key + 1].startTime)
        {
            $scope.$apply(function()
            {
                $scope.setActive(key);
            });
        }
    });
});

That all works until the seeked time reaches the end of the array and $scope.data[key + 1].time is undefined. How should I approach this? My mind isn't on track right now and I still haven't had my coffee :|

edit

new function working

player.addEventListener("seeked", function(event)
{
    currentTime = player.currentTime;
    for (var i = 0; i <= $scope.data.length; i++)
    {
        if ($scope.data[i + 1] != undefined)
        {
            if (currentTime < $scope.data[i + 1].startTime)
            {
                $scope.$apply(function()
                {
                    $scope.setActive(i);
                });
                break;
            }
        }
        else
        {
            $scope.$apply(function()
            {
                $scope.setActive($scope.data.length - 1);
            });
        }
    }
});

javascript
jquery
arrays
angularjs

Answer 1

Test for the array element's existence first. If it fails, the other tests will be ignored:

if ($scope.data[key+1] && currentTime>=$scope.data[key].startTime && currentTime<=$scope.data[key+1].startTime)

Answer 2

You will need a check for [key + 1] to ensure you don't try to access an element beyond the length of the array.

player.addEventListener("seeked", function(event)
{
    currentTime = player.currentTime;
    angular.forEach($scope.data, function(value, key)
    {
        if ( ($scope.data[key+1] != undefined) && currentTime < $scope.data[key+1].startTime)
        {
           // this is the one we are after
           return false; // exit foreach
        } else {
          // we are on the last one.
        }
    });
});

Answer 3

Here was the final solution that worked

player.addEventListener("seeked", function(event)
{
    currentTime = player.currentTime;
    for (var i = 0; i <= $scope.data.length; i++)
    {
        if ($scope.data[i + 1] != undefined)
        {
            if (currentTime < $scope.data[i + 1].startTime)
            {
                $scope.$apply(function()
                {
                    $scope.setActive(i);
                });
                break;
            }
        }
        else
        {
            $scope.$apply(function()
            {
                $scope.setActive(i - 1);
            });
        }
    }
});