## Comparable Interface

Objects that have an ordering are compared using the compareTo() method.

### 13. Ordered Array

**Answer:**

Comparison Zero, Negative, or Positive " 9999" .compareTo ("023") negative "(rat)" .compareTo ("[cat]") negative "23.5" .compareTo ("23,7") positive "More Cheese?" .compareTo ("More Cheese!") positive "cobol" .compareTo ("cobalt") positive

# Ordered Array

The elements of an **ordered** array are arranged in ascending (or descending) order. In general, an ordered array can have duplicate elements. (In some situations, though, an array is guaranteed not to have duplicates.) The picture shows an array of `ints`

arranged into ascending order.

The elements of an array can be arranged in order by using a static `sort()`

method of the `Arrays`

class.

// Sort the array into ascending order

static void sort( array )

There are `sort()`

methods for arrays of type `byte[]`

, `char[]`

, `double[]`

, `float[]`

, `int[],`

and `long[]`

. There is also a method that can sort object references based on the values of the objects.

Sorting is an important process in computer programming. Many data processing operations depend on data that is sorted, much as the data in a filing cabinet is kept sorted.

**Question 13:**

Would a dictionary be useful if its definitions were not in sorted order?