Pattern matching for switch in Java 17

24 Oct 2023

patternmatching

Java 17 introduces a new feature called “Pattern Matching for Switch” that enhances the ability to use pattern matching in switch statements. This feature aims to simplify code and make it more concise and readable. Let’s delve into how it works and explore some examples.

What is Pattern Matching for Switch?

Pattern matching for switch is an enhancement to the existing switch statement in Java. It allows you to use patterns in case labels and extract values from those patterns directly within the switch block. This feature simplifies code that involves multiple if-else conditions or switch statements with complex conditions.

How to use Pattern Matching for Switch?

To utilize pattern matching for switch, we need to follow these steps:

Define a pattern in the case label.
Use the case keyword followed by the pattern.
Inside the switch block, use the case keyword followed by the same pattern, but without the variable name.
Access the matched value directly within the block.

Here’s an example to demonstrate the usage:

public class PatternMatchingExample {
    public static void main(String[] args) {
        Object obj = "Hello";

        switch (obj) {
            case String s -> System.out.println("String: " + s);
            case Integer i -> System.out.println("Integer: " + i);
            case Double d -> System.out.println("Double: " + d);
            default -> System.out.println("Unknown type");
        }
    }
}

In the above example, we define patterns in the case labels. When the switch expression matches one of the patterns, it executes the corresponding block. Notice how we’ve directly accessed the matched values s, i, and d within the respective blocks.

Benefits of Pattern Matching for Switch

Using pattern matching for switch offers several benefits:

Concise code: Pattern matching simplifies code by eliminating the need for additional if-else conditions or nested switch statements.
Readability: Patterns make the intent of code more apparent, improving the readability of switch statements.
Direct access to matched values: Pattern matching allows direct access to matched values within the switch block, reducing the need for separate assignments or additional logic.

Conclusion

Pattern matching for switch is a new feature introduced in Java 17 that allows using patterns and extracting values directly within switch statements. It simplifies code and improves readability by eliminating the need for complex conditions and additional logic. This feature provides concise and direct access to matched values, enhancing the overall programming experience in Java. Start leveraging pattern matching for switch in your Java 17 projects and take advantage of its benefits.

References:

#java #patternmatching