Pattern matching for switch in Java 16

24 Oct 2023

PatternMatching

Java 16 introduces a new enhancement to the switch statement called pattern matching for switch. This feature allows for more concise and expressive code when working with multiple case statements.

How it Works

With pattern matching for switch, you can now use patterns as the case labels instead of explicit values. This enables you to write more flexible and readable code. Let’s take a look at an example:

public String dayOfTheWeek(int day) {
    return switch (day) {
        case 1 -> "Monday";
        case 2 -> "Tuesday";
        case 3 -> "Wednesday";
        case 4 -> "Thursday";
        case 5 -> "Friday";
        case 6 -> "Saturday";
        case 7 -> "Sunday";
        default -> throw new IllegalArgumentException("Invalid day");
    };
}

In this example, we use the arrow (->) notation to define the mapping between the patterns and the corresponding value to be returned. The switch statement automatically selects the appropriate case based on the pattern matching evaluation.

Pattern Matching Syntax

Pattern matching for switch supports various patterns, including:

Constant Patterns: These patterns match against specific constant values, just like traditional case statements.
Type Patterns: These patterns check if the given value matches a certain type.
Enumeration Patterns: These patterns match against enumeration constants.
Combining Patterns: You can combine multiple patterns using logical operators such as | (OR) and & (AND).

Here’s an example showcasing different pattern combinations:

public void process(Object obj) {
    switch (obj) {
        case null -> System.out.println("Null value");
        case String s -> System.out.println("String value: " + s);
        case Integer i && i > 0 -> System.out.println("Positive integer: " + i);
        case Integer i -> System.out.println("Integer value: " + i);
        case Double d -> System.out.println("Double value: " + d);
        default -> System.out.println("Other value");
    }
}

Benefits of Pattern Matching for Switch

Pattern matching for switch brings several benefits to Java developers:

Concise Code: Using patterns as case labels reduces the need for multiple if-else statements or extensive switch blocks, making the code shorter and easier to read.
Type Safety: The ability to use type patterns ensures that the code is type-safe, preventing potential runtime errors.
Improved Readability: Pattern matching allows for more expressive code that closely resembles the natural language, making it easier to understand and maintain.
Seamless Integration: The pattern matching feature seamlessly integrates with existing switch statements, minimizing the need for major code refactoring.

Conclusion

Pattern matching for switch in Java 16 provides a powerful addition to the language, allowing developers to write more concise and expressive code when dealing with multiple case statements. By leveraging various patterns, you can create flexible and readable code that enhances productivity and maintainability.

Give it a try in your Java 16 projects and experience the benefits of this new feature firsthand!

References

#hashtags #Java16 #PatternMatching