Android™ How to Program, Second Edition

Notes on the Expression in Each case of a switch

When using the switch statement, remember that each case must contain a constant integral expression—that is, any combination of integer constants that evaluates to a constant integer value (e.g., –7, 0 or 221). An integer constant is simply an integer value. In addition, you can use character constants—specific characters in single quotes, such as 'A', '7' or '$'—which represent the integer values of characters and enum constants (introduced in Section D.10).

The expression in each case can also be a constant variable—a variable containing a value which does not change for the entire program. Such a variable is declared with keyword final (discussed in Appendix D). Java has a feature called