NSPredicate to test for NULL, and blank strings

ios objective-c nspredicate
Doz picture Doz · Sep 10, 2011 · Viewed 57.5k times · Source

I have an NSArray and need to filter out any strings that are null or rather, have ' ' (empty string). How do I do that? I have tried doing:

NSPredicate *predicateName = [NSPredicate predicateWithFormat:@"(name!=nil)"];

but that doesn't seem to work. Or maybe it does but there are different kinds of null...

Answer

Dave DeLong picture Dave DeLong · Sep 10, 2011

If you don't use Core Data, you could do:

NSPredicate *predicateName = [NSPredicate predicateWithFormat:@"name.length > 0"];

If the string is empty, this will fail (because 0 == 0). Similarly, if name is nil, it will also fail, because [nil length] == 0.

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