Comparable Interface

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

16. String Sorting Program

Answer:
Yes. So an array of String references can be sorted.

String Sorting Program

Here is a program that demonstrates how sort() is used with an array of String references.

Notice the use of the for-each loops.

The output of the program is:

Scrambled array:  bat fox gnu eel ant dog fox gnat
Sorted    array:  ant bat dog eel fox fox gnat gnu

import java.util.Arrays;

class ArrayDemoTwo
{
  public static void main ( String[] args )
  {
    String[] animals = {"bat", "fox", "gnu", "eel", "ant", "dog", "fox", "gnat" };
    
    System.out.print("Scrambled array:  ");
    for ( String anm : animals )
      System.out.print( anm + " ");
      
    System.out.println();
    
    Arrays.sort( animals );
    
    System.out.print("Sorted    array:  ");
    for ( String anm : animals )
      System.out.print( anm + " ");
      
    System.out.println();
       
  }
}

Question 16:
To use sort() with a class that you define, what interface must that class implement?