13af6ab5fSopenharmony_ci/*
23af6ab5fSopenharmony_ci * Copyright (c) 2023-2024 Huawei Device Co., Ltd.
33af6ab5fSopenharmony_ci * Licensed under the Apache License, Version 2.0 (the "License");
43af6ab5fSopenharmony_ci * you may not use this file except in compliance with the License.
53af6ab5fSopenharmony_ci * You may obtain a copy of the License at
63af6ab5fSopenharmony_ci *
73af6ab5fSopenharmony_ci * http://www.apache.org/licenses/LICENSE-2.0
83af6ab5fSopenharmony_ci *
93af6ab5fSopenharmony_ci * Unless required by applicable law or agreed to in writing, software
103af6ab5fSopenharmony_ci * distributed under the License is distributed on an "AS IS" BASIS,
113af6ab5fSopenharmony_ci * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
123af6ab5fSopenharmony_ci * See the License for the specific language governing permissions and
133af6ab5fSopenharmony_ci * limitations under the License.
143af6ab5fSopenharmony_ci */
153af6ab5fSopenharmony_ci
163af6ab5fSopenharmony_ciclass Residence {
173af6ab5fSopenharmony_ci    numberOfRooms: Int = 1;
183af6ab5fSopenharmony_ci}
193af6ab5fSopenharmony_ci
203af6ab5fSopenharmony_ciclass Person {
213af6ab5fSopenharmony_ci    residence: Residence = new Residence();
223af6ab5fSopenharmony_ci}
233af6ab5fSopenharmony_ci
243af6ab5fSopenharmony_cifunction dummy(): Person | null {
253af6ab5fSopenharmony_ci    return null;
263af6ab5fSopenharmony_ci}
273af6ab5fSopenharmony_ci
283af6ab5fSopenharmony_cifunction main(): void {
293af6ab5fSopenharmony_ci    let john: Person | null = dummy();
303af6ab5fSopenharmony_ci    let test = john?.residence?.numberOfRooms;
313af6ab5fSopenharmony_ci    assert (test == null);
323af6ab5fSopenharmony_ci    let nullsafety_test = john?.residence?.numberOfRooms ?? "unknown";
333af6ab5fSopenharmony_ci    assert (nullsafety_test == "unknown");
343af6ab5fSopenharmony_ci}
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