Question

I have a NSMutableArray of objects, below is the struct:

//object at index i
locations {
   NSString* address;
   NSString* state;
   NSNumber* distance;
}

I have 10000 object like the above structure in the NSMutableArray.
How do order this array so that the locations are in order by the NSNumber distance?

I tried this:

lowToHigh = [NSSortDescriptor sortDescriptorWithKey:@"distance" ascending:YES];
[locationArray sortUsingDescriptors:[NSArray arrayWithObject:lowToHigh]];

is using the sortDescriptorWithKey:@"distance" wrong? since distance isn’t actually a key, it NSNumber* distance.

edit in my header @property (strong, nonatomic)NSNumber* _distance; and then @synthesize _distance = distance; in my methods file but this is in locationObjects.* object class. Then I import this in my current class I am doing this sorting. Is that an issue?
How I import is locationObjects* locObj = [[locationObjects alloc] init];

Answer 1

This is what I use:

NSSortDescriptor *lowToHigh = [[NSSortDescriptor alloc] initWithKey:@"distance"
                                              ascending:YES];
NSArray *mySortDescriptors = [NSArray arrayWithObject:lowToHigh];
NSArray *sortedArray = [locationArray sortedArrayUsingDescriptors:mySortDescriptors];