在JavaScript中调用父“类”上的函数

function Parent() {
  this.name = 'Parent';
}

Parent.prototype.sayHello = function() {
  console.log('Hello from Parent');
}

function Child() {
  Parent.call(this);
  this.name = 'Child';
}

Child.prototype = Object.create(Parent.prototype);
Child.prototype.constructor = Child;

Child.prototype.sayHello = function() {
  // 调用父类的sayHello方法
  Parent.prototype.sayHello.call(this);
  console.log('Hello from Child');
}

var child = new Child();
child.sayHello();

class Parent {
  constructor() {
    this.name = 'Parent';
  }

  sayHello() {
    console.log('Hello from Parent');
  }
}

class Child extends Parent {
  constructor() {
    super();
    this.name = 'Child';
  }

  sayHello() {
    // 调用父类的sayHello方法
    super.sayHello();
    console.log('Hello from Child');
  }
}

var child = new Child();
child.sayHello();