How can I update the NSString property/variable after it changed?

Question

I am confused about some items on the iOS developer site and require explanation. In the below cases A, B the property / variable is going to get updated, but it doesn't. The page where the below code resides.

These are the property/variable

• A) self.badgeView.firstName
• B) NSDate *originalDate

These are the 2 snippets of code:

NSMutableString *nameString = [NSMutableString stringWithString:@"John"];   
self.badgeView.firstName = nameString; 
[nameString appendString:@"ny"];
NSDate *originalDate = self.lastModificationDate;
self.lastModificationDate = [NSDate date]; 
NSLog(@"Last modification date changed from %@ to %@", originalDate, self.lastModificationDate);

Answer 1

Those NSString properties, if implemented The Right Way , will copy the parameter you pass.

NSMutableString *nameString = [NSMutableString stringWithString:@"John"];   
self.badgeView.firstName = nameString; 
[nameString appendString:@"ny"];
// you'll have to update it again, if you want that view's string updated:
self.badgeView.firstName = nameString;