13af6ab5fSopenharmony_ci/* 23af6ab5fSopenharmony_ci * Copyright (c) 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 X { 173af6ab5fSopenharmony_ci public foo: number 183af6ab5fSopenharmony_ci 193af6ab5fSopenharmony_ci constructor() { 203af6ab5fSopenharmony_ci this.foo = 0 213af6ab5fSopenharmony_ci } 223af6ab5fSopenharmony_ci} 233af6ab5fSopenharmony_ci 243af6ab5fSopenharmony_ciclass Y { 253af6ab5fSopenharmony_ci public foo: number 263af6ab5fSopenharmony_ci constructor() { 273af6ab5fSopenharmony_ci this.foo = 0 283af6ab5fSopenharmony_ci } 293af6ab5fSopenharmony_ci} 303af6ab5fSopenharmony_ci 313af6ab5fSopenharmony_cilet x = new X() 323af6ab5fSopenharmony_cilet y = new Y() 333af6ab5fSopenharmony_ci 343af6ab5fSopenharmony_ciconsole.log("Assign X to Y") 353af6ab5fSopenharmony_ciy = x 363af6ab5fSopenharmony_ci 373af6ab5fSopenharmony_ciconsole.log("Assign Y to X") 383af6ab5fSopenharmony_cix = y 393af6ab5fSopenharmony_ci 403af6ab5fSopenharmony_ci 413af6ab5fSopenharmony_ci 423af6ab5fSopenharmony_ci 433af6ab5fSopenharmony_ciinterface Z { 443af6ab5fSopenharmony_ci foo: number 453af6ab5fSopenharmony_ci } 463af6ab5fSopenharmony_ci 473af6ab5fSopenharmony_ci // X implements interface Z, which makes relation between X and Y explicit. 483af6ab5fSopenharmony_ci class C implements Z { 493af6ab5fSopenharmony_ci public foo: number 503af6ab5fSopenharmony_ci 513af6ab5fSopenharmony_ci constructor() { 523af6ab5fSopenharmony_ci this.foo = 0 533af6ab5fSopenharmony_ci } 543af6ab5fSopenharmony_ci } 553af6ab5fSopenharmony_ci 563af6ab5fSopenharmony_ci // Y implements interface Z, which makes relation between X and Y explicit. 573af6ab5fSopenharmony_ci class C2 implements Z { 583af6ab5fSopenharmony_ci public foo: number 593af6ab5fSopenharmony_ci 603af6ab5fSopenharmony_ci constructor() { 613af6ab5fSopenharmony_ci this.foo = 0 623af6ab5fSopenharmony_ci } 633af6ab5fSopenharmony_ci } 643af6ab5fSopenharmony_ci 653af6ab5fSopenharmony_ci let x1: Z = new C() 663af6ab5fSopenharmony_ci let y1: Z = new C2() 673af6ab5fSopenharmony_ci 683af6ab5fSopenharmony_ci console.log("Assign X to Y") 693af6ab5fSopenharmony_ci y1 = x1 // ok, both are of the same type 703af6ab5fSopenharmony_ci 713af6ab5fSopenharmony_ci console.log("Assign Y to X") 723af6ab5fSopenharmony_ci x1 = y1 // ok, both are of the same type