js中四种创建对象的方式

一、

var user = new Object();
user.first="Brad";
user.last="Dayley";
user.getName = function( ) { return this.first + " " + this.last; }

二、

var user = {
  first: 'Brad',
  last: 'Dayley',
  getName: function( ) { return this.first + " " + this.last; }};

 三、

function zch(first, last) {
    this.first = first;
    this.last = last;
    this.getName = function () {
        return this.first + " " + this.last;
    };
}

var user = new zch("zheng", "chunhao");
console.log(user.getName());

 四、

function User(first, last){
    this.first = first;
    this.last = last;
}
User.prototype = {
    getFullName: function(){
        return this.first + " " + this.last;
    },
    sayHello: function(){
        console.log('hello,zhengchunhao.');
    }
};

var zch = new User("zheng", "chunhao");
console.log(zch.getFullName());

zch.sayHello();