How do I return the entire set / array using NSPredicate?

Question

I'm building a carArray and want to filter the contents conditionally, using an NSPredicate, like so:

NSPredicate *pred;
switch (carType) {
  case FreeCar:
    pred = [NSPredicate predicateWithFormat:@"premium = NO"];
    break;
  case PremiumCar:
    pred = [NSPredicate predicateWithFormat:@"premium = YES"];
    break;
  default:
    pred = [NSPredicate predicateWithFormat:@"SOME PREDICATE THAT RETURNS EVERYTHING"];
    break;
}
self.carArray = [aCarArrayIGotFromSomewhere filteredArrayUsingPredicate:pred];

My question is, what is the correct syntax for the value I've stubbed in as SOME PREDICATE THAT RETURNS EVERYTHING which returns all of the instances in the array / set?

Answer 1

To return all of the contents a given array / set, filter using the value TRUEPREDICATE. Also, if for any reason you wanted to none of the contents of an array / set, try the country cousin of TRUEPREDICATE, FALSEPREDICATE.

For more information about NSPredicate format string syntax, check the relevant docs.