switch
- Java course
- Beginner
- Lesson 39/116
- 4 min
Learn multi-branch with switch.
switch
switch branches on the value of a variable. case lists values, break exits, default is the fallback branch.
int day = 1;
switch (day) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
default:
System.out.println("Unknown");
}switch works with int, String, enum and wrapper types. Without break; after a case, execution falls through to the next case; this is called fall-through.
switch flow
Without break, execution falls through to the next case. This is called fall-through:
int day = 1;
switch (day) {
case 1:
case 2:
System.out.println("Weekday");
break;
default:
System.out.println("Weekend");
}Here both 1 and 2 print "Weekday". Fall-through is useful to bind several values to the same block. Forgetting break by mistake is a common error; write each branch carefully.
Practice Print the day name
Write a Main class with a main method. Assign 2 to int day. With switch (day) print "Monday" for case 1:, "Tuesday" for case 2:, "Unknown" for default:. Add break; after each case.
Sample solution
public class Main {
public static void main(String[] args) {
int day = 2;
switch (day) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
default:
System.out.println("Unknown");
}
}
}Expected output
Tuesday
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match the switch concepts
| Term | Meaning |
|---|---|
switch |
Selection |
case |
Branch |
break |
Exit |
default |
Fallback |
2 What does break do in a switch?
- Starts a loop
- Falls to next case
- Nothing
- Exits the switch Correct answer
Explanation: break exits the switch and continues after it.
3 Complete the case branch
int day = 1;
switch (day) {
____ 1:
System.out.println("Monday");
break;
}int day = 1;
switch (day) {
case 1:
System.out.println("Monday");
break;
}Explanation: case 1: marks the first branch.