1 /* 2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test 26 * @bug 8206986 27 * @compile --enable-preview -source 12 ExpressionSwitchFallThrough.java 28 * @run main/othervm --enable-preview ExpressionSwitchFallThrough 29 */ 30 31 import java.util.Objects; 32 import java.util.function.Function; 33 34 public class ExpressionSwitchFallThrough { 35 public static void main(String... args) { 36 new ExpressionSwitchFallThrough().run(); 37 } 38 39 private void run() { 40 runTest(this::expression1); 41 runTest(this::expression2); 42 } 43 44 private void runTest(Function<T, String> print) { 45 check(T.A, print, "ab"); 46 check(T.B, print, "b"); 47 check(T.C, print, ""); 48 } 49 50 private String expression1(T t) { 51 String help = ""; 52 return switch (t) { 53 case A: help = "a"; 54 case B: help += "b"; 55 default: break help; 56 }; 57 } 58 59 private String expression2(T t) { 60 String help = ""; 61 return switch (t) { 62 case A: help = "a"; 63 case B: help += "b"; 64 default: break help; 65 }; 66 } 67 68 private void check(T t, Function<T, String> print, String expected) { 69 String result = print.apply(t); 70 if (!Objects.equals(result, expected)) { 71 throw new AssertionError("Unexpected result: " + result); 72 } 73 } 74 75 enum T { 76 A, B, C; 77 } 78 }