The Comparable Interface Type

• object1.compareTo(object2) returns
  • Negative number if object1 less than object2
  • 0 if objects identical
  • Positive number if object1 greater than object2
• sort method compares and rearranges elements
  if (object1.compareTo(object2) > 0) . . .
• String class implements Comparable<String> interface type: lexicographic (dictionary) order
• Country class: compare countries by area
  Ch4/sort1/Country.java
  Ch4/sort1/CountrySortTester.java