1/* 2 * Copyright (c) 2021 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 Parent { 17 constructor(x) { 18 this.x = x; 19 } 20 21 static toString() { 22 return 'parent'; 23 } 24} 25 26class Child extends Parent { 27 constructor(x, y) { 28 super(x); 29 this.y = y; 30 } 31 32 value() { 33 return this.x * this.y; 34 } 35 36 static toString() { 37 return super.toString() + ' child'; 38 } 39} 40 41var c = new Child(2, 3); 42print(c.value()); 43print(Child.toString());