楔子

Tyler 講的 prototype 的觀念蠻清楚 & 簡單的，稍做一下記錄 Tyler McGinnis javascript

prototype

Prototype is a property of a function that point to an object when function is created.

用下面的例子就可以來解釋上面的句子

function imAFunction () {}
imAFunction.prototype // {constructor: f}

把共用的 Method 放在一起包裝在一個 Object 內

// 共用的 method
const animalMethods() {
  eat () {},
  sleep () {},
  play () {}
}

function Animal (name, energy) {
  let animal = Object.crete(animalMethods)
  animal.name = name
  animal.energy = energy

  return animal
}

關鍵字 new

new 做的就只是把 Object.create 做修正一下

function AnimalWithNew (name, energy) {
  this = Object.create(Animal.prototype)
  this.name = name
  this.energy = energy

  return this
}

let snoppy = new AnimalWithNew('snoopy', 100)