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 Z { 17 foo: number; 18} 19 20 21 // X implements interface Z, which makes relation between X and Y explicit. 22class C implements Z { 23 public foo: number 24 public bar: string; 25 26 constructor() { 27 this.foo = 0 28 this.bar = "Class C"; 29 } 30 } 31 32 // Y implements interface Z, which makes relation between X and Y explicit. 33 class C2 implements Z { 34 public foo: number; 35 public bar: boolean 36 37 constructor() { 38 this.foo = 0; 39 this.bar = true; 40 } 41 } 42 43 let x1: Z = new C() 44 let y1: Z = new C2() 45 let x2 = new C() 46 let y2 = new C2() 47 48console.log("Assign X to Y") 49y2 = x2 // ok, both are of the same type 50 51console.log("Assign X to Y") 52y1 = x1 // ok, both are of the same type 53 54console.log("Assign Y to X") 55x1 = y1 // ok, both are of the same type 56