var obj1 = new Object();  // 构造函数方式创建
var obj2 = {};  // 对象字面量方式创建

var obj1 = new Object(100 + 1);
alert(obj1);  // 101

var obj1 = new Object(100);
obj1 += 100;
alert(typeof obj1);  // "number"

function num() {return 100;}
var obj1 = new Object(num);
alert(obj1());  // 100
alert(typeof obj1);  // "function"

var obj1 = new Object();
obj1.name = "Jack";
obj1.sayName = function () {
    return this.name;
};
obj1["year age"] = "1992 25";  // 关联数组赋值
alert(obj1["year age"]);  // "1992 25"

var obj2 = {  // 动态赋值也可以用于字面量
    name : "Eson",
    sayName : function () {
        return this.name;
    },
    "year age" : "1992 25"
};
alert(obj2["year age"]);  // "1992 25"

function displayInfo(obj) {
    return obj.name + " " + obj.age;
}
alert(displayInfo({
    name : "Nopi",
    age : 25
}));  // "Nopi 25"

var obj2 = {
    name : "Jack",
    age : 25
};
with (obj2) {
    var str = "姓名：" + name + "\n";
    str += "年龄：" + age;
}
alert(str);  // "姓名：Jack 年龄：25"

var obj2 = {
    name : "Jack",
    age : 25
};
for (var p in obj2) {
    alert(p);  // "name"  "age"
}