Execises

J.3 Define each of the following terms:

a. Collection

b. Collections

c. Comparator

d. List

e. HashMap

f. ObjectOutputStream

g. File

h. ObjectOutputStream

i. byte-based stream

j. character-based stream

J.4 Briefly answer the following questions:

a. What is the primary difference between a Set and a Map?

b. What happens when you add a primitive type (e.g., double) value to a collection?

c. Can you print all the elements in a collection without using an Iterator? If yes, how?

J.5 (Duplicate Elimination) Write a program that reads in a series of first names and eliminates duplicates by storing them in a Set. Allow the user to search for a first name.

J.6 (Counting Letters) Modify the program of Fig. J.9 to count the number of occurrences of each letter rather than of each word. For example, the string