Calculating Distance between two coordinates using CLLocation

Question

I'm using CLLocationDistance to get the distance between two points, but I'm getting an error when passing my current location in it.

CLLocation *current = [[CLLocation alloc] initWithLatitude:startLocation.coordinate.latitude longitude:startLocation.coordinate.longitude];
CLLocation *itemLoc = [[CLLocation alloc] initWithLatitude:[[[getName objectAtIndex:indexPath.row] objectForKey:@"lat"] doubleValue] longitude:[[[getName objectAtIndex:indexPath.row] objectForKey:@"lon"] doubleValue]];

//Here the current location gives me an error "Initializing cllocation with an expression incompatible format"
CLLocationDistance *itemDist = [itemLoc distanceFromLocation:current];
NSLog(@"Distance: %@", itemDist);

Answer 1

The error you're getting is actually:

Initializing 'CLLocationDistance *' (aka 'double *') with an expression of incompatible type 'CLLocationDistance' (aka 'double')

What it's saying is you're initializing itemDist (which you've declared as a CLLocationDistance *) to something that is returning a CLLocationDistance (notice no asterisk).

CLLocationDistance is not an object.
It is just a primitive type (specifically double -- see the Core Location Data Types Reference).

So instead of declaring itemDist as a pointer to a CLLocationDistance, just declare it as a CLLocationDistance (no asterisk):

CLLocationDistance itemDist = [itemLoc distanceFromLocation:current];

You'll also need to update the NSLog to expect a double instead of an object otherwise it will crash at run-time:

NSLog(@"Distance: %f", itemDist);

Answer 2

Is swift 2.0 is in the following way:

let userLocation:CLLocation = CLLocation(latitude: 11.11, longitude: 22.22)
let priceLocation:CLLocation = CLLocation(latitude: 33.33, longitude: 44.44)
let meters:CLLocationDistance = userLocation.distanceFromLocation(priceLocation)

Answer 3

Below code will work for you in view load

//************************** GEtting USer's latitude/ Longitude ********************




  self.locationManager = [[CLLocationManager alloc] init];
        self.locationManager.delegate = self;
        [self.locationManager startUpdatingLocation];
//************************** GEtting USer's latitude/ Longitude ********************

pragma mark - CLLocationManagerDelegate

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
    NSLog(@"didFailWithError: %@", error);
    UIAlertView *errorAlert = [[UIAlertView alloc]
                               initWithTitle:@"Error" message:@"Failed to Get Your Location" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [errorAlert show];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    NSLog(@"didUpdateToLocation: %@", newLocation);
    CLLocation *currentLocation = newLocation;
    if (currentLocation != nil) {        
        CLLocation *locA = [[CLLocation alloc] initWithLatitude:currentLocation.coordinate.longitude longitude:currentLocation.coordinate.latitude];
        CLLocation *locB = [[CLLocation alloc] initWithLatitude:11.111111111111111 longitude:11.1111111111111111]; 
        User_Vanue_Distance = [locA distanceFromLocation:locB];
        NSLog(@"THIS IS THE DISTANCE BT TWO POINTS +++++++++++++++++++++%f",User_Vanue_Distance);  
    }
}

You need to put below keys in info.plist, in ios 8 to access location we need to put below keys in info.plist 1. NSLocationWhenInUseUsageDescription : Location required 2. NSLocationAlwaysUsageDescription Needed : Location Needed

This will work for you but one thing you need to add is add a check for ios8. otherwise this will crash on ios 7

// Check for iOS 8. Without this guard the code will crash with "unknown selector" on iOS 7.


  if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
        [self.locationManager requestWhenInUseAuthorization];
    }

Hope this will work for you. :)

Answer 4

To find distance in KM from two different Lat & Long

let userLocation:CLLocation = CLLocation(latitude: 23.0320, longitude: 72.5250)
let priceLocation:CLLocation = CLLocation(latitude: 23.0283, longitude: 72.5067)
let distance = String(format: "%.2f km", userLocation.distanceFromLocation(priceLocation)/1000)
print("Distance is KM is:: \(distance)")