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I'm trying to create then retrieve an array of CLLocationCoordinate2D objects, but for some reason the array is always empty.
I have:
NSMutableArray *currentlyDisplayedTowers; CLLocationCoordinate2D new_coordinate = { currentTowerLocation.latitude, currentTowerLocation.longitude }; [currentlyDisplayedTowers addObject:[NSData dataWithBytes:&new_coordinate length:sizeof(new_coordinate)] ]; I've also tried this for adding the data:
[currentlyDisplayedTowers addObject:[NSValue value:&new_coordinate withObjCType:@encode(struct CLLocationCoordinate2D)] ]; And either way, the [currentlyDisplayedTowers count] always returns zero. Any ideas what might be going wrong?
Thanks!
250
The primary difference between NSArray and NSMutableArray is that a mutable array can be changed/modified after it has been allocated and initialized, whereas an immutable array, NSArray , cannot.
The latitude and longitude associated with a location, specified using the WGS 84 reference frame.
The NSMutableArray class declares the programmatic interface to objects that manage a modifiable array of objects. This class adds insertion and deletion operations to the basic array-handling behavior inherited from NSArray . NSMutableArray is “toll-free bridged” with its Core Foundation counterpart, CFMutableArray .
NSArray creates static arrays, and NSMutableArray creates dynamic arrays. You can use arrays when you need an ordered collection of objects. NSArray is “toll-free bridged” with its Core Foundation counterpart, CFArrayRef . See Toll-Free Bridging for more information on toll-free bridging.
To stay in object land, you could create instances of CLLocation and add those to the mutable array.
CLLocation *towerLocation = [[CLLocation alloc] initWithLatitude:lat longitude:lon]; [currentDisplayedTowers addObject:towerLocation]; To get the CLLocationCoordinate struct back from CLLocation, call coordinate on the object.
CLLocationCoordinate2D coord = [[currentDisplayedTowers lastObject] coordinate]; If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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