Filtering NSArray of NSDictionary objects using NSPredicate

Question

I have an NSArray of NSDictionary objects. I want to filter the array based on keys of the dictionaries using NSPredicate. I have been doing something like this:

Answer 1

When using a dynamic key, you should use the %K token instead of %@. You also don't want the quotes around the value token. They will cause your predicate to test for equality against the literal string @"%@" instead of against value.

NSString *predicateString = [NSString stringWithFormat:@"%K == %@", key, value];

This is documented in the Predicate Format String Syntax guide.

---

Edit: As Anum Amin points out, +[NSString stringWithFormat:] doesn't handle predicate formats. You want [NSPredicate predicateWithFormat:@"%K == %@", key, value] instead.

Answer 2

For me, Kevin's answer did not work. I used:

NSPredicate *predicateString = [NSPredicate predicateWithFormat:@"%K contains[cd] %@", keySelected, text];//keySelected is NSString itself
        NSLog(@"predicate %@",predicateString);
        filteredArray = [NSMutableArray arrayWithArray:[YourArrayNeedToFilter filteredArrayUsingPredicate:predicateString]];