JS 學習 object

Object vs Function/new Function

var iama = {};
var iamb = function(){};

if(iama instanceof Object){
  console.log(typeof(iama)); //output: "object"
}


if(iamb instanceof Function){
  console.log(typeof(iamb)); //output: "function"
}

var iamc = new iamb();
console.log(typeof(iamc ));  //output: "object"

new function 出來的 instance 會是 object
new object 會出現 TypeError

用 prototype 定義object的變數與函式

var animal = function() {};

animal.prototype = {
 bark:"woo",
 legs:4,
 setEat:function(){}
};
animal.prototype.name = "lucky";

var dog = new animal();
dog.bark = "wang";
dog.setEat();

用 prototype 來做繼承

//animal.prototype.constructor;
var animal = function() {
 this.bark = "woo";
 this.legs = 4;
 this.setEat=function(){}
};

var dog =  function() {
 this.bark = "wang";
};
dog.prototype = new animal();  //dog繼承animal

var lucky = new dog();
console.log(lucky.bark);
console.log(lucky.legs);

* 當物件找不到指定的屬性/函式，會去他的 prototype 找，找不到時會再找 prototype 的 prototype ，一直找到最基本幾乎什麼都沒有的 Object 為止。

大致是這樣，嗯?