Remove "(null)" from string if no value available - ios

Question

In have an app where I show the user's current position in address. The problem is that if example the Postal Code or Administrative Area isn't available, the string prints (null) where that value should be staying - all the other data is there.
Example:
(null) Road No 19
(null) Mumbai
Maharashtra
What I was wondering was if it was possible to just have a blank space instead of (null)?
My current code:
_addressLabel.text = [NSString stringWithFormat: #"%# %#\n%# %#\n%#",
placemark.subThoroughfare, placemark.thoroughfare,
placemark.postalCode, placemark.locality,
placemark.administrativeArea];

Answer 1

This is very easily accomplished with the NSString method
- (NSString *)stringByReplacingOccurrencesOfString:(NSString *)target withString:(NSString *)replacement
For example, after you have populated your _addressLabel.text string with all of the (possibly nil) values, just replace the occurrences of the undesired string with the desired string. For example, the following will solve your problem.
_addressLabel.text = [NSString stringWithFormat: #"%# %#\n%# %#\n%#",
placemark.subThoroughfare, placemark.thoroughfare,
placemark.postalCode, placemark.locality,
placemark.administrativeArea];
// that string may contain nil values, so remove them.
NSString *undesired = #"(null)";
NSString *desired = #"\n";
_addressLabel.text = [_addressLabel.text stringByReplacingOccurrencesOfString:undesired
withString:desired];

Answer 2

Use an NSMutableString, and have some if statements which append a string to it if the value isn't [NSNull null] or nil.
CLPlacemark *placemark = ...;
NSMutableString *address = [NSMutableString string];
if (placemark.subThoroughfare) {
[address appendString:placemark.subThoroughfare];
}
if (...) {
[address appendFormat:#"%#\n", ...];
}
// etc...
_addressLabel.text = address;

Answer 3

Use this to replace null with empty string
addressLabel.text = [NSString stringWithFormat: #"%# %#\n%# %#\n%#",
placemark.subThoroughfare?:#"", placemark.thoroughfare?:#"",
placemark.postalCode?:#"", placemark.locality?:#"",
placemark.administrativeArea?:#""];

Answer 4

I believe a cleaner(*) solution is to use the "?" operator here, like this, for each of the string values:
Instead of placemark.subThoroughfare write:
(placemark.subThoroughfare ? placemark.subThoroughfare : #"")
or even shorter:
(placemark.subThoroughfare ?: #"")
This will check if the value is NULL (or nil) - if non-zero, it'll use the string's value, otherwise it'll use a string containing a space.
It's cleaner because my solution does not depend on how NULL strings are printed, i.e. if they get printed in a future OS version as (nil) instead of (null), then my solution will still work, while Brian Tracy's won't. Not that I expect that to be a problem, ever, just pointing out what's a more proper solution to the issue out hand, for those who care what's going on behind the scenes.