NSArray with NSPredicate using NOT IN

95
votes

I have an NSArray that I want to filter out certain objects using an NSPredicate, I was hoping I could use NOT IN since I saw that I can easily do an IN.

So I have my array:

self.categoriesList

Then I get the values I want to remove:

NSArray *parentIDs = [self.cateoriesList valueForKeyPath:@"@distinctUnionOfObjects.ParentCategoryID"];

This gives me a list of ParentCategoryID's for categories I DO NOT want to display, so I figure I can use an NSPredicate to remove them:

self.cateoriesList = [self.cateoriesList filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"CategoryID NOT IN %@",parentIDs]];

This fails:

reason: 'Unable to parse the format string "CategoryID NOT IN %@"'

If I wanted to use just IN that works perfectly of course.

2
iosobjective-cnsarraynspredicate

2 Answers

230
votes

What about NOT (CategoryID IN %@)?

2
votes

How about using NONE?

[NSPredicate predicateWithFormat:@"NONE CategoryID IN %@", parentIDs];