NSDate finding nearest date to today

Question

I have a sorted array of NSDates. Can someone help with how I can find the date in the array that is closest to the current date?

I need to get the index of the date closest so that I can scroll to that date in my tableview.

For example, if I have Jan 1 2013, Jan 6 2013, Jan 9 2013 and Jan 10 2013. I want the index of Jan 6 2013.

Hope that makes sense. Thanks for the help.

UPDATE:

I am trying this:

    NSTimeInterval interval = 0;
    NSUInteger indexOfDate;
    for (NSDate * date in m_arEventsSorted)
    {               
        if(abs([date timeIntervalSinceDate:[NSDate date]]) < interval)
        {
            interval = abs([date timeIntervalSinceDate:[NSDate date]]);
            indexOfDate = [m_arEventsSorted indexOfObject:date];
        }
    }

Answer 1

NSDate provides the timeIntervalSinceNow (reference) method which returns a NSTimeInterval (a typedef'd double). Simply use the fabs() function on this to find the smallest difference between each date and now.

Answer 2

I would recommend the timeIntervalSinceDate: function. Something like this (code not tested!):

NSDate *currentDate = [NSDate date];
double min = [currentDate timeIntervalSinceDate:[array objectAtIndex:0]];
int minIndex = 0;
for (int i = 1; i < [array count]; ++i)
{
     double currentmin = [currentDate timeIntervalSinceDate:[array objectAtIndex:i]];
     if (currentmin < min) {
           min = currentmin;
           minIndex = i;
     }
}

You can get the closest index from minIndex.

Answer 3

This should work:

NSDate *closestDate;
for( NSDate *tempDate in dates ){
    NSInteger tempDateInterval = [tempDate timeIntervalSinceNow];
    //to work with positive and negative time difference
    if( tempDateInterval < 0 ){
        tempDateInterval *= -1;
    }
    NSInteger closestDateInterval = [closestDate timeIntervalSinceNow];
    if( closestDateInterval < 0 ){
        closestDateInterval *= -1;
    }
    if( tempDateInterval < closestDateInterval ){
        closestDate = tempDate;
    }
}