知乎专栏 |
package cn.netkiller.demo; public class DemoSwitch { public DemoSwitch() { } public static void main(String[] args) { var number = 4; var operation = "平方"; var result = switch (operation) { case "立方" -> { yield number * number * number; } case "平方" -> { yield number * number; } default -> number; }; System.out.println(result); } }
不必为break每个 case 块定义一个语句,我们可以简单地使用箭头语法
int money = 3; String cn = switch (money) { case 1 -> "壹"; case 2 -> "贰"; case 3 -> "叁"; case 4 -> "肆"; case 5 -> "伍"; case 6 -> "陆"; case 7 -> "柒"; case 8 -> "捌"; case 9 -> "玖"; case 10 -> "拾"; default -> "零"; }; System.out.println(cn);
package cn.netkiller.test; public class Test { public static void main(String[] args) { withSwitchExpression(Fruit.APPLE); withReturnValue(Fruit.AVOCADO); withYield(Fruit.VEGETABLES); } private static void withSwitchExpression(Fruit fruit) { switch (fruit) { case APPLE, PEAR -> System.out.println("普通水果"); case MANGO, AVOCADO -> System.out.println("进口水果"); default -> System.out.println("未知水果"); } } private static void withReturnValue(Fruit fruit) { System.out.println(switch (fruit) { case APPLE, PEAR -> "普通水果"; case MANGO, AVOCADO -> "进口水果"; default -> "未知水果"; }); } private static void withYield(Fruit fruit) { String text = switch (fruit) { case APPLE, PEAR, MANGO, AVOCADO -> { System.out.println("水果: " + fruit); yield "水果: " + fruit; } case VEGETABLES -> { System.out.println("蔬菜: " + fruit); yield "蔬菜:" + fruit; } default -> { yield "未知食物"; } }; System.out.println(text); } public enum Fruit { APPLE, PEAR, MANGO, AVOCADO, VEGETABLES } }