Arrays - Java - page 386

TIP: Enumerated Types in switch Statements ★

A single program with both type definitions ( Flavor and Berry ) could use both
Flavor.STRAWBERRY and Berry.STRAWBERRY .
So, when can you use STRAWBERRY instead of Flavor.STRAWBERRY ? The approximate
answer is that you use STRAWBERRY instead of Flavor.STRAWBERRY when there is enough
context for the compiler to know STRAWBERRY means STRAWBERRY as defined in the type
Flavor . For example, in a switch statement, if the type of the controlling expression is
Flavor , then STRAWBERRY can only mean Flavor.STRAWBERRY . This rule will help in
remembering when to use STRAWBERRY and when to use Flavor.STRAWBERRY . But, some-
times you may simply have to check a reference or try the two possibilities out and see
which one (or ones) the compiler accepts.

■

Display 6.16 Enumerated Type in a switch Statement

1 import java.util.Scanner;

2
3 public class EnumSwitchDemo
4{
5

enum Flavor {VANILLA, CHOCOLATE, STRAWBERRY};

6 public static void main(String[] args)

7 {

8 Flavor favorite = null ;

9 Scanner keyboard = new Scanner(System.in);

10 System.out.println("What is your favorite flavor?");

11 String answer = keyboard.next();

12 answer = answer.toUpperCase();

13 favorite = Flavor.valueOf(answer);

The case labels must have just the name of
the value without the type name and dot.

14 switch (favorite)

15 {

16 case VANILLA:

17 System.out.println("Classic");

18 break;

19 case CHOCOLATE:

20 System.out.println("Rich");

21 break;

22 default :

23 System.out.println("I bet you said STRAWBERRY.");

24 break;

25 }

26 }

27 }