Answer:

indexOf returns 2

Details

phonebook class

Things are getting a little complicated. It would be good to look at some details.

  1. An ArrayList of entries is made.
  2. Several Entry objects are put into the list.
  3. A target Entry object is created.
  4. The indexOf() searches for the target in the list.
    • The equals(Object) method of Entry is used.
    • The picture shows the first comparison (which returns false).
  5. A match is found at cell number 2

The indexOf(Object) method is a member of the ArrayList, but it uses the equals(Object) method of Entry.

QUESTION 24:

Would playing with the program help?