function Human(name){

  this.name = name;

  this.printName = function () {

    console.log(`My Name is ${this.name}`)

  }

}

​

function GoodMan(name){

  Human.call(this, name);

  this.selfTalk = function () {

    this.printName()

  }

}

​

var chris = new GoodMan('Chris');

​

// 可以唷

chris.selfTalk()

​

// "error"

setTimeout(chris.selfTalk, 1000)

​

// 自行綁定

setTimeout(chris.selfTalk.bind(chris), 1000)

​

​

​