Using the result from exercise 2, modify the lookup: method to search the address book for all matches. Have the method return an array of all such matching address cards, or nil if no match is made....

Using the result from exercise 2, modify the lookup: method to search the address book for all matches. Have the method return an array of all such matching address cards, or nil if no match is made. Make the change to the version that uses the sortedArrayUsingSelector: method, as well as to the one presented at the end of this chapter that uses the indexesOfObjectsPassingTest: method instead. (Note that the example presented at the end of this chapter returns an NSIndexSet result, but we want an array of AddressCards here.)