Sort array of NSDictionaries by a value inside one of the keys [duplicate]

Question

I'm pulling an XML feed from a server, the feed contains train stations and their latitude and longitude locations.

I've managed to create an NSArray full of NSDictionary objects, each corresponding to a station.

In the dictionary there is a key for latitude and key for longitude. I also have a CLLocation object with the location of the device.

I know how to calculate the distance between the device and each station, but the distance isn't part of the dictionary. I would like to sort the array in order of distance from the device.

How would I do that? No idea where to start on this and Google or my books aren't being very helpful to me! Any help is much appreciated.

Answer 1

Use the following;

NSArray *sortedArray;
sortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *first, NSDictionary *second) {
    // Calculate distances for each dictionary from the device
    // ...
    return [firstDistance compare:secondDistance];
}];