Strings in switch Statements

 Since: Jdk 1.7

public class SwitchStringExample {

      public static void main(String[] args) {

           

            String day = callSwich("Monday");

            System.out.println(day);

     

            /** NullPointerException */

            day = callSwich(null);

            System.out.println(day);

      }

      private static String callSwich(String day) {

           String typeOfDay;

           switch (day) {

               case "Monday":

                   typeOfDay = "Start of work week";

                   break;

               case "Tuesday":

               case "Wednesday":

               case "Thursday":

                   typeOfDay = "Midweek";

                   break;

               case "Friday":

                   typeOfDay = "End of work week";

                   break;

               case "Saturday":

               case "Sunday":

                   typeOfDay = "Weekend";

                   break;

               default:

                   throw new IllegalArgumentException("Invalid day" + day);

           }

           return typeOfDay;

      }

}

The switch statement compares the String object in its expression with the expressions associated with each case label as if it were using the String.equals method; consequently, the comparison of String objects in switch statements is case sensitive. The Java compiler generates generally more efficient bytecode from switch statements that use String objects than from chained if-then-else statements.

Note:

Make sure to add a NULL check to avoid NullPointerException.