Computer Science 121
Example using doubles and an if-else statement.

import java.io.*;

// An application with a class that provides information about a person’s age and voting eligibility.
class People
{
     public static void main (String [] args)
     {
          Person person = new Person ();
          person.readData ();
          person.votingAge ();
     } // main method
} // class People

// Class that stores information about a person's name and age.
class Person
{
     private String name;
     private double age;

     // A method to read data from the keyboard.  It uses a buffered reader.
     public void readData ()
     {
          try
          {
               BufferedReader stdin = new BufferedReader (new InputStreamReader (System.in));
               System.out.print ("Name: ");
               name = stdin.readLine ();
               System.out.print ("Age: ");
               age = Double.valueOf (stdin.readLine ()).doubleValue ();
           }
          catch (IOException e) { System.out.println ("I/O error");}
          catch (NumberFormatException ex) { System.out.println ("Number format error.");}
     } // method readData

     // Method that decides whether or not a person is old enough to vote..
     public void votingAge ()
     {
          if (age >= 18.0)
               System.out.println (name + " is old enough to vote.");
          else
               System.out.println (name + " is still too young to vote.");
     } // method votingAge
} // class Person