NSArray *array;
[array objectAtIndex:0]; // <- Will throw an error

RecordingLocation* closest;

//find the closest recording location
for (...)
{
    //try to find the closest object...
    //suppose we don't find anything so closest is never set.
}

if (closest!=nil)
    NSLog(@"Closest: %f,%f",closest.x,closest.y);

NSArray *arr = [NSArray arrayWithObjects:@"@dog","@cat",nil];