Objective-C dictionary inserting a BOOL

Question

OK, I'm a little confused. It's probably just a triviality.

I've got a function which looks something like this:

- (void)getNumbersForNews:(BOOL)news andMails:(BOOL)mails {
NSMutableDictionary *parameters = [[NSMutableDictionary alloc] init];
[parameters setValue:news  forKey:@"getNews"];
[parameters setValue:mails forKey:@"getMails"];...}

It doesn't matter whether I use setValue:forKey: or setObject:ForKey:, I'm always getting a warning:

"Passing argument 1 of set... makes pointer from integer without a cast"...

How on earth do I insert a bool into a dictionary?

Answer 1

Objective-C containers can store only Objective-C objects so you need to wrap you BOOL in some object. You can create a NSNumber object with [NSNumber numberWithBool] and store the result.
Later you can get your boolean value back using NSNumber's -boolValue.

Answer 2

You can insert @"YES" or @"NO" string objects and Cocoa will cast it to bool once you read them back.

Otherwise I'd suggest creating dictionary using factory method like dictionaryWithObjectsAndKeys:.

Answer 3

A BOOL is not an object - it's a synonym for an int and has 0 or 1 as its values. As a result, it's not going to be put in an object-containing structure.

You can use NSNumber to create an object wrapper for any of the integer types; there's a constructor [NSNumber numberWithBool:] that you can invoke to get an object, and then use that. Similarly, you can use that to get the object back again: [obj boolValue].

Answer 4

Values in an NSDictionary must be objects. To solve this problem, wrap the booleans in NSNumber objects:

[parameters setValue:[NSNumber numberWithBool:news] forKey:@"news"];
[parameters setValue:[NSNumber numberWithBool:mails] forKey:@"mails"];