Java 7 for Absolute Beginners

CHAPTER 4 ■ OPERATORS

characters.add(drWatson);
// sort by the natural values (uses compareTo())
Collections.sort(characters);
for (int i = 0; i < characters.size(); i++) {
Person person = characters.get(i);
System.out.println(person.firstName + " "

• person.lastName + " likes " + person.favoriteBook);
  }
  System.out.println();
  System.out.println("Sorting by favorite book");
  // sort by book (uses the Comparator)
  Collections.sort(characters, new BookComparator());
  for (int i = 0; i < characters.size(); i++) {
  Person person = characters.get(i);
  System.out.println(person.firstName + " "


• person.lastName + " likes " + person.favoriteBook);
  }
  }
  }

And Listing 4-34 shows the output from our test class.

Listing 4-34. CompareTest output

false
true

Sorting by name
Sherlock Holmes likes The Sign of the Four
Sam Spade likes The Maltese Falcon
John Watson likes A Study in Scarlet
John Watson likes A Study in Scarlet

Sorting by favorite book
John Watson likes A Study in Scarlet
John Watson likes A Study in Scarlet
Sam Spade likes The Maltese Falcon
Sherlock Holmes likes The Sign of the Four

Summary

In this chapter, we learned:

• Java has a large number of operators.


• Java's operators have precedence (that is, some operators are processed before
  other operators).


• Java has some seemingly odd operators (such as the bitwise operators) but that
  they all have their uses.