New Feature of JDK13

java

New Features of JDK13

1.Switch Expressions(Preview)

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public class SwitchDemo {
    public static void main(String[] args) {
        int month = 1;
        int year = 2001;

        // switch expressions can be used in complex expressions:
        int minutes = 24 * switch (month) {
            case 1, 3, 5, 7, 8, 10, 12 -> 31;
            case 4, 6, 9, 11 -> 30;
            case 2 -> isLeapYear(year) ? 29 : 28;
            default -> throw new IllegalArgumentException("The month should in range(1～12)!");
        } * 60;

        System.out.println(String.format("There are %d minutes in month %d, year %d.", minutes, month, year));

    }

    private static boolean isLeapYear(int year){
        return year % 400 == 0 || (year % 100 != 0 && year %4 == 0);
    }
}

The output of above code:

switch_expression

2.Text Blocks (Preview)

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public class MultiLineStringDemo {
    public static void main(String[] args) {
        String multiLine = """
            Down by the salley gardens
            My love and I did meet
            She passed the salley gardens
            With little snow-white feet
            She bid me take love easy
            As the leaves grow on the tree
            But I being young and foolish
            With her would not agree
        """;

        multiLine.lines().map(s -> s + "🎵").forEach(System.out::println);
    }

}

The output of above code:

multilinestring