The switch statement is one of the selection statements in Java. It provides a convenient way to select and execute a block of code based on the value of an expression. The switch statement evaluates the expression once and then matches the value of the expression with the values specified in the case labels.
How the switch case works
When the switch statement is executed, it evaluates the expression inside the switch and compares it with the values specified in the case labels. If a match is found, the corresponding block of code following that case label is executed. If no match is found, the code block following the default label (if present) is executed.
The break statement
By default, after executing a block of code associated with a case label, the switch statement continues executing the code from the next case label unless a break statement is encountered. The break statement is used to exit the switch block and prevent the execution of subsequent case blocks. It is essential to include a break statement at the end of each case block to avoid unintended fall-through behavior.
The default case
The default case is optional in a switch statement. It is executed when no match is found between the expression value and the case labels. If a default case is provided, the code block following the default label will be executed. It is typically used to handle situations where none of the other case conditions are met.
In this tutorial, we’ll show you some examples of how to use the switch statement in Java.
switch statement, the if-else statement is another selection statement that we can use to execute our code conditionally in our Java program.Supported Argument Types
The switch statement accepts specific types of arguments in Java. Here are the supported argument types:
charbyteshortintCharacterByteShortIntegerenumString
String type arguments to the switch statement for value comparison.Example 1: Using int Type Argument
Let’s start with an example that demonstrates the usage of the switch statement with an int type argument:
IntSwitchStatementExample.java
public class IntSwitchStatementExample {
public static void main(String[] args) {
// Using int type argument in the switch statement
int monthNumber = 6;
switch (monthNumber) {
case 1:
System.out.println("Month number " + monthNumber + " is January");
break;
case 2:
System.out.println("Month number " + monthNumber + " is February");
break;
case 3:
System.out.println("Month number " + monthNumber + " is March");
break;
case 4:
System.out.println("Month number " + monthNumber + " is April");
break;
case 5:
System.out.println("Month number " + monthNumber + " is May");
break;
case 6:
System.out.println("Month number " + monthNumber + " is June");
break;
case 7:
System.out.println("Month number " + monthNumber + " is July");
break;
case 8:
System.out.println("Month number " + monthNumber + " is August");
break;
case 9:
System.out.println("Month number " + monthNumber + " is September");
break;
case 10:
System.out.println("Month number " + monthNumber + " is October");
break;
case 11:
System.out.println("Month number " + monthNumber + " is November");
break;
case 12:
System.out.println("Month number " + monthNumber + " is December");
break;
default:
System.out.println("Month number " + monthNumber + " is an invalid month");
}
}
}Output:
Month number 6 is JuneExample 2: Using String Type Argument
Now, let’s explore an example that showcases the usage of the switch statement with a String type argument:
StringSwitchStatementExample.java
public class StringSwitchStatementExample {
public static void main(String[] args) {
// Using String type argument in the switch statement
String day = "Saturday";
switch (day) {
case "Monday":
case "Tuesday":
case "Wednesday":
case "Thursday":
case "Friday":
System.out.println(day + " is weekday");
break;
case "Saturday":
case "Sunday":
System.out.println(day + " is weekend");
break;
default:
System.out.println(day + " is an invalid day");
}
}
}Output:
Saturday is weekendExample 3: Using enum Type Argument
In addition to int and String types, the switch statement can also accept enum type arguments. Here’s an example:
EnumSwitchStatementExample.java
public class EnumSwitchStatementExample {
public static void main(String[] args) {
// Using enum type argument in the switch statement
Day day = Day.TUESDAY;
switch (day) {
case MONDAY:
case TUESDAY:
case WEDNESDAY:
case THURSDAY:
case FRIDAY:
System.out.println(day + " is a weekday");
break;
case SATURDAY:
case SUNDAY:
System.out.println(day + " is a weekend");
break;
default:
System.out.println(day + " is an invalid day");
}
}
}
enum Day {
MONDAY, TUESDAY, WEDNESDAY, THURSDAY, SATURDAY, SUNDAY
}Output:
TUESDAY is a weekdayExample 4: Using byte Type Argument
Here is an example that demonstrates the usage of the switch statement with an byte type argument:
ByteSwitchStatementExample.java
public class ByteSwitchStatementExample {
public static void main(String[] args) {
byte dayOfWeek = 4;
switch (dayOfWeek) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
case 3:
System.out.println("Wednesday");
break;
case 4:
System.out.println("Thursday");
break;
case 5:
System.out.println("Friday");
break;
case 6:
System.out.println("Saturday");
break;
case 7:
System.out.println("Sunday");
break;
default:
System.out.println("Invalid day");
}
}
}Output:
ThursdayExample 5: Using short Type Argument
This is an example of using an short type argument:
ShortSwitchStatementExample.java
public class ShortSwitchStatementExample {
public static void main(String[] args) {
short statusCode = 200;
switch (statusCode) {
case 200:
System.out.println("Success");
break;
case 404:
System.out.println("Not Found");
break;
case 500:
System.out.println("Internal Server Error");
break;
default:
System.out.println("Unknown status code");
}
}
}Output:
SuccessExample 6: Nested switch Statements
Nested switch statements allow for more complex control flow and decision-making by nesting one switch statement within another.
int dayOfWeek = 3;
int timeOfDay = 2;
switch (dayOfWeek) {
case 1:
case 2:
case 3:
case 4:
case 5:
switch (timeOfDay) {
case 1:
case 2:
System.out.println("Working hours");
break;
case 3:
case 4:
System.out.println("After-work hours");
break;
default:
System.out.println("Invalid time");
}
break;
case 6:
case 7:
System.out.println("Weekend");
break;
default:
System.out.println("Invalid day");
}Output:
Working hoursSummary
In this tutorial, we explored the switch statement in Java and learned how to use it with different argument types. The switch statement provides a concise way to handle multiple possible values of an expression. By using case labels, you can direct the flow of your code based on specific value matches. Remember to include break statements to prevent unintended fall-through behavior. The default case provides a fallback option when no matches are found. With the examples provided, you can now apply the switch statement effectively in your Java programs.
You can find the example codes from this tutorial on GitHub.