This topic is about Java 12 – Switch Expressions.
Java 12 introduces expressions to Switch statement and released it as a preview feature. Following are the changes introduced in case of new switch with expressions −
- No fallthrough.
- No break statment required to prevent fallthrough.
- A single case can have multiple constant labels.
- Default case is compulsary now.
Consider the following example −
ApiTester.java
public class APITester {
public static void main(String[] args) {
System.out.println("Old Switch");
System.out.println(getDayTypeOldStyle("Monday"));
System.out.println(getDayTypeOldStyle("Saturday"));
System.out.println(getDayTypeOldStyle(""));
System.out.println("New Switch");
System.out.println(getDayType("Monday"));
System.out.println(getDayType("Saturday"));
System.out.println(getDayType(""));
}
public static String getDayType(String day) {
String result = switch (day) {
case "Monday", "Tuesday", "Wednesday","Thursday", "Friday" -> "Weekday";
case "Saturday", "Sunday" -> "Weekend";
default -> {
break "Invalid day.";
}
};
return result;
}
public static String getDayTypeOldStyle(String day) {
String result = null;
switch (day) {
case "Monday":
case "Tuesday":
case "Wednesday":
case "Thursday":
case "Friday":
result = "Weekday";
break;
case "Saturday":
case "Sunday":
result = "Weekend";
break;
default:
result = "Invalid day.";
}
return result;
}
}
Compile and Run the program
$javac -Xlint:preview --enable-preview -source 12 APITester.java $java --enable-preview APITester
Output
Old Switch Weekday Weekend Invalid day. New Switch Weekday Weekend Invalid day.
In this topic we learned about Java 12 – Switch Expressions. To know more, Click Here.