ES5原型琏继承

function add(){};

add.prototype.showName = "MAN";
add.prototype.name = function(){
    console.log(this.showName);
}

new add().name();

var cat = {};
Object.getPrototypeOf(cat).showName = "dog";
cat.__proto__.master = "yang";
cat.age = 2;
cat["max"] = "岁";
alert(cat.showName+""+cat.age+""+cat["max"]+""+cat.master);