创建对象

var car = new Object();
var car = {};

var car = {
    color : "red",
    run : function(){alert("run")}
};

car.color;  //"red"
car.run();//alert("run")
car["color"];
car["run"]();

增加属性和方法

car.type = "suv";

修改

car.color = "white";

删除

delete car.color;

元素构建

car.constructor;   //Object

constructor

var num = new Number(123);
num.constructor;//Number

toString

var num = new Number(123);
num.toString()  //"123"

valueOf

var num = new Number(123);
num.valueOf();  //123

hasOwnProperty

var car = {
    color : "red",
    run : function(){alert("run")}
};
car.hasOwnProperty("color") //true
car.hasOwnProperty("logo")  //false