1/* 2 * Copyright (c) 2023-2023 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 Z { 17 foo: number; 18} 19 20interface Z1 { 21 bar: string; 22} 23 24 // X implements interface Z, which makes relation between X and Y explicit. 25 class C implements Z, Z1 { 26 public foo: number 27 public bar: string; 28 29 constructor() { 30 this.foo = 0 31 this.bar = "Class C"; 32 } 33 } 34 35 // Y implements interface Z, which makes relation between X and Y explicit. 36 class C2 implements Z, Z1 { 37 public foo: number; 38 public bar: string; 39 40 constructor() { 41 this.foo = 0; 42 this.bar = "Class C2"; 43 } 44 } 45 46 let x1: Z = new C() 47 let y1: Z1 = new C2() 48 49console.log("Assign X to Y") 50y1 = x1 // ok, both are of the same type 51 52console.log("Assign Y to X") 53x1 = y1 // ok, both are of the same type 54