distanceFromLocation - Calculate distance between two points

Question

Just a quick question on Core Location, I'm trying to calculate the distance between two points, code is below:

    -(void)locationChange:(CLLocation *)newLocation:(CLLocation *)oldLocation     {         // Configure the new event with information from the location.         CLLocationCoordinate2D newCoordinate = [newLocation coordinate];         CLLocationCoordinate2D oldCoordinate = [oldLocation coordinate];          CLLocationDistance kilometers = [newCoordinate distanceFromLocation:oldCoordinate] / 1000; // Error ocurring here.         CLLocationDistance meters = [newCoordinate distanceFromLocation:oldCoordinate]; // Error ocurring here. } 

I'm getting the following error on the last two lines:

error: cannot convert to a pointer type

I've been searching Google, but I cannot find anything.

Answer 1

Try this instead:

CLLocationDistance meters = [newLocation distanceFromLocation:oldLocation]; 

The method you're trying to use is a method on a CLLocation object :)

Answer 2

The distance is calculated between 2 CLLocations and not between to coordinates.

You need to use these coordinates to get the CLLocations for the respective coordinates using the following line of code

CLLocation *newLocation = [[CLLocation alloc] initWithCoordinate: newCoordinate altitude:1 horizontalAccuracy:1 verticalAccuracy:-1 timestamp:nil]; 

Similarly for the other coordinate and then you can calculate the distance between these two locations using the following line of code

CLLocationDistance kilometers = [newLocation distanceFromLocation:oldLocation] / 1000; 

Hope this will help you.

Update: Swift 3.0

let distanceKiloMeters = (newLocation.distance(from: oldLocation))/1000