1/* 2 * Copyright (c) 2024 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16interface I 17{ 18 field? : String | Number; 19} 20 21abstract class C implements I 22{ 23 field_? : Object | String; 24 25 get field() : Object | String | undefined { 26 return this.field_; 27 } 28 29 set field(o : Object | String | undefined) { 30 this.field_ = o; 31 } 32} 33 34/* @@? 25:13 Error TypeError: field(): Object|undefined in C cannot override field(): undefined|String|Double in I because overriding return type is not compatible with the other return type. */ 35/* @@? 25:13 Error TypeError: Method field(): Object|undefined in C not overriding any method */ 36