Handle more conditional branches with new Switch expressions in Java 13

Handle more conditional branches with the new Switch expressions in Java 13

With the release of Java 13, we have welcomed many new features and improvements. One of the exciting new features is enhanced Switch expressions to better handle conditional branches. In this article, we will introduce how to use the new Switch expression in Java 13 to handle more conditional branches and give some code examples.

In the past, in Java, we usually used the Switch statement to handle conditional branches. However, the Switch statement has some limitations, such as it can only match constant expressions, and a break or return statement must be used between each case statement to avoid executing the next case statement. These limitations make the Switch statement somewhat unwieldy when dealing with complex conditional logic.

The new Switch expression introduced in Java 13 eliminates these limitations and provides a more flexible and concise syntax. Let's take a look at how to use the new Switch expression to handle more conditional branches.

First of all, we can use multiple expressions as conditions for matching in Switch expressions. Previously, we could only use an expression as a condition in a Switch statement. Now, we can use multiple expressions separated by commas.

The sample code is as follows:

String fruit = "apple";
int count = switch (fruit) {
    case "apple", "orange" -> 10;
    case "banana" -> 20;
    default -> throw new IllegalArgumentException("Invalid fruit: " + fruit);
};
System.out.println("Count: " + count);

In the above example, we used two conditions in the Switch expression, namely "apple" and "orange". If the value of fruit is "apple" or "orange", then the value of count will be 10. If the value of fruit is "banana", then the value of count will be 20. If the value of fruit does not meet any conditions, an IllegalArgumentException is thrown.

Another useful new feature is that Switch expressions no longer require an explicit break or return statement to end each case branch. Now, we can directly return a value in each case branch.

The sample code is as follows:

String fruit = "apple";
int count = switch (fruit) {
    case "apple" -> {
        System.out.println("Apple");
        yield 10;
    }
    case "orange" -> {
        System.out.println("Orange");
        yield 20;
    }
    default -> {
        throw new IllegalArgumentException("Invalid fruit: " + fruit);
    }
};
System.out.println("Count: " + count);

In the above example, we can use curly brackets in each case branch to execute multiple statements, and directly use the yield keyword to return a value.

In addition, Java 13 also introduces new arrow syntax ("->") and yield keyword, making Switch expressions more concise and readable.

To summarize, the new Switch expression in Java 13 enhances the processing of conditional branches. We can use multiple expressions as conditions for matching, and no longer need to explicitly use break or return statements to end each case branch, making the code more concise and readable. I hope this article helps you better understand and apply the new Switch expressions in Java 13.

Reference:

• https://openjdk.java.net/jeps/354

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