JavaScript面向对象基础

一, 对象的基本操作

1. 创建对象

// 创建空白对象
var obj1 = {};
var obj2 = new Object();

// 创建包含初始值的对象
var person = {
    "Name": "Terry",
    "age": 27,
    "sex:": "male"
};

alert(person.Name); // Terry
alert(person.sex); // male

 

2. 对象访问

下面代码显示访问对象属性的两种方法

var person = {};
person.name = "Terry";
person["age"] = 27;
alert(person.name + " " + person.age);

var nameList = {
    name1: "n1",
    "name2": "n2",
    name3: "n3"
};

var strName;

// 访问nameList中的值-1
for (var name in nameList) {
    strName += nameList[name] + " ";
}
alert(strName);
strName = "";

// 访问nameList中的值-2
for (var i = 0; i < 3; i++) {
    strName += nameList["name" + (i + 1)];
}

3. delete可以删除某对象中的属性；判断某属性是否存在在一个对象可以用in操作符

var nameList = {
    name1: "n1",
    "name2": "n2",
    name3: "n3"
};

alert(nameList.name1); // n1
delete nameList.name1;

alert("name1" in nameList); // false

3. constructor属性-对应对象初始化时的构造函数

var date = new Date();
alert(date.constructor); // Date
alert(date.constructor == Date);// true