1/*
2 * Copyright (c) 2023 - 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
16class Residence {
17    numberOfRooms: int = 1;
18}
19
20class Person {
21    residence: Residence = new Residence();
22}
23
24function hasResidence(person: Person | null) : boolean {
25    return person?.residence != null;
26}
27
28function main(): void {
29    let john = null;
30    assert(hasResidence(john) == false);
31}
32