The switch statement is used to execute different
blocks of code based on the value of an expression. It is
useful when you need to compare one value against several
possible cases.
A switch statement checks an expression and selects
the matching case.
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;
case 3:
System.out.println("Wednesday");
break;
default:
System.out.println("Invalid day");
}
}
}Tuesday
Since day is 2, the code inside
case 2 executes.
Basic syntax:
switch (expression) {
case value1:
// Code for value1
break;
case value2:
// Code for value2
break;
default:
// Code when no case matches
}switch evaluates the expression.case specifies a possible matching value.break exits the switch statement.default handles unmatched values and is optional.break statement is commonly used to
prevent execution from continuing into the next case.
You can use a switch statement to select an action based on an integer value.
public class Main {
public static void main(String[] args) {
int choice = 3;
switch (choice) {
case 1:
System.out.println("Add");
break;
case 2:
System.out.println("Subtract");
break;
case 3:
System.out.println("Multiply");
break;
case 4:
System.out.println("Divide");
break;
default:
System.out.println("Invalid choice");
}
}
}Multiply
Change choice to 1, 2, or 4 to display
the corresponding operation.
The default block executes when no case
matches the switch expression. It is similar to the
final else block in an if-else ladder.
public class Main {
public static void main(String[] args) {
int number = 10;
switch (number) {
case 1:
System.out.println("One");
break;
case 2:
System.out.println("Two");
break;
default:
System.out.println("Number not found");
}
}
}Number not foundThe value 10 does not match either case, so the default block executes.
In a traditional switch statement, break
exits the switch. Without it, execution can continue
into subsequent case blocks. This behavior is called
fall-through.
public class Main {
public static void main(String[] args) {
int number = 1;
switch (number) {
case 1:
System.out.println("One");
case 2:
System.out.println("Two");
case 3:
System.out.println("Three");
break;
default:
System.out.println("Other");
}
}
}One
Two
Three
Because the first case has no break,
execution continues through cases 2 and 3.
break when you want to execute only
the matching case. Intentional fall-through is also
possible when multiple cases should share behavior.
Java supports String expressions in switch statements. String cases are matched by their contents and are case-sensitive.
public class Main {
public static void main(String[] args) {
String language = "Java";
switch (language) {
case "Java":
System.out.println("Java Programming");
break;
case "Python":
System.out.println("Python Programming");
break;
case "PHP":
System.out.println("PHP Programming");
break;
default:
System.out.println("Unknown language");
}
}
}Java Programming
If you change the value to "java", the
"Java" case will not match because the
comparison is case-sensitive.
A switch statement can also check a
char value.
public class Main {
public static void main(String[] args) {
char grade = 'A';
switch (grade) {
case 'A':
System.out.println("Excellent");
break;
case 'B':
System.out.println("Very Good");
break;
case 'C':
System.out.println("Good");
break;
case 'F':
System.out.println("Fail");
break;
default:
System.out.println("Invalid grade");
}
}
}Excellent
Character literals use single quotation marks, such
as 'A'.
Multiple case labels can share the same block of code. This is useful when several values should produce the same result.
public class Main {
public static void main(String[] args) {
int day = 7;
switch (day) {
case 1:
case 7:
System.out.println("Weekend");
break;
case 2:
case 3:
case 4:
case 5:
case 6:
System.out.println("Weekday");
break;
default:
System.out.println("Invalid day");
}
}
}Weekend
Both case 1 and case 7 execute the same block because
they appear before the same break.
Modern Java supports switch expressions that return a
value. The arrow syntax (->) avoids
accidental fall-through.
public class Main {
public static void main(String[] args) {
int day = 2;
String result = switch (day) {
case 1 -> "Monday";
case 2 -> "Tuesday";
case 3 -> "Wednesday";
default -> "Other day";
};
System.out.println(result);
}
}TuesdaySwitch expressions were finalized in Java 14. This syntax is available in Java 14 and later.
Modern switch expressions allow multiple case labels to point to the same result using commas.
public class Main {
public static void main(String[] args) {
int day = 6;
String type = switch (day) {
case 1, 7 -> "Weekend";
case 2, 3, 4, 5, 6 -> "Weekday";
default -> "Invalid day";
};
System.out.println(type);
}
}WeekdayThis syntax can make code shorter and easier to read when multiple values share the same result.
| Switch | If-Else |
|---|---|
| Useful for matching one expression against several values. | Useful for ranges and complex Boolean conditions. |
Uses case labels. |
Uses Boolean conditions. |
Traditional switch may need break. |
Does not use case fall-through. |
| Supports compatible types such as int, char, enum, and String. | Can test a wider variety of Boolean expressions. |
Example using if-else:
int marks = 75;
if (marks >= 90) {
System.out.println("Grade A");
} else if (marks >= 60) {
System.out.println("Grade B");
} else {
System.out.println("Grade C");
}An if-else ladder is more suitable here because the conditions check ranges of marks.
// Traditional switch
switch (choice) {
case 1:
System.out.println("One");
break;
case 2:
System.out.println("Two");
break;
}// Invalid: duplicate case value
// case 1: ...
// case 1: ...String language = "java";
switch (language) {
case "Java":
System.out.println("Java selected");
break;
default:
System.out.println("No exact match");
}No exact matchA default case is optional, but including one is often helpful for handling unexpected values.
This program uses a switch statement to select an arithmetic operation.
public class Main {
public static void main(String[] args) {
double a = 20;
double b = 5;
char operator = '/';
switch (operator) {
case '+':
System.out.println("Result: " + (a + b));
break;
case '-':
System.out.println("Result: " + (a - b));
break;
case '*':
System.out.println("Result: " + (a * b));
break;
case '/':
if (b != 0) {
System.out.println("Result: " + (a / b));
} else {
System.out.println("Cannot divide by zero.");
}
break;
default:
System.out.println("Invalid operator");
}
}
}Result: 4.0switch selects a block based on a value.case defines matching values.break prevents traditional case fall-through.default handles unmatched values.Q1. Which keyword exits a traditional switch block?
Q2. Which block handles unmatched case values?
Q3. What is the output?
int day = 1;
switch (day) {
case 1:
System.out.println("Monday");
break;
default:
System.out.println("Other");
}