Update README.md

README.md

 
 ### Part I:
 
-Create a PhoneBook class that holds names and phone numbers. You can use an associative data type (one which stores items as keys paired with values).
+Create a PhoneBook class that holds names and phone numbers. You can use an associative data type (one which stores items as keys paired with values). (Hint: You should use a sorted map).
 
 Your PhoneBook class should have the following method
   * lookup(String name) -  allows you to look up a person's phone number based on their name
   * remove(String name) - remove entry
   * display() - list all entries (names an phone numbers) in alphabetical order
 
+    ```java
+      PhoneBook phoneBook = new PhoneBook();
+      phoneBook.add("Zebra", "111-222-333");
+      phoneBook.add("Dog", "222-444-4444");
+      phoneBook.display(); 
+      
+      /*
+       Calling display this should print out the entries like this
+       Dog 222-444-4444
+       Zebra 111-222-333
+      */
+      
+    ```
+
 ### Part II:
 
 Add a `reverseLookup()` method to PhoneBook. This method should allow you to look up names by the phone number associated with them.