Question

Basically my dictionary looks like:

object:[NSNumber numberWithBool:] key: [NSNumber numberWithInteger:ID]

I want to add objects to a NSMutableDictionary if they don’t exist already. I also want to overwrite any values of NO with YES if there are two IDs that are the same and one value is a YES.

e.g.

ID:5, YES
ID:5, NO
ID:5, YES

I want the result to be ID:5 YES in my dictionary. I do this:

if ([dict objectForKey:[NSNumber numberWithInteger:conditionsListID]] != nil) {
   [dict setObject:[NSNumber numberWithBool:theValue forKey:[NSNumber numberWithInteger:conditionsListID];
else {
  if (theValue) {
       [dict setObject:[NSNumber numberWithBool:theValue forKey:[NSNumber numberWithInteger:conditionsListID];

  }
}
}

I was wondering if it matters if I even check if the value that exists already has NO, or if I just overwrite it if my new value has YES or not since in the end, YES is what I want. Is there really any difference between the two? Thanks.

Answer 1

Just call setObject:forKey: and the dictionary will take care of the logic you want. According to the API docs:

“If aKey already exists in the dictionary, the dictionary’s previous value object for that key is sent a release message and anObject takes its place.”