Javascript对象的技巧和陷阱

标签：javascript   对象   继承   

创建对象的3种方法

方法1

直接创建

var obj = {
            name: "mike",
            age: 10
        }

方法2

用new创建

var ob = new Date();

方法3

ECMAScript5有个新的方法 Object.create()

其实这个方法就是继承某一个对象

var obj = {
            name: "mike",
            age: 10
        };

        var newobj = Object.create(obj);
        console.log(newobj.name);

一些技巧和陷阱

1

var a = {
            name: "mike",
            name: "john"
        }
        console.log(a["name"]);

2

var a = {};
        a.x = 1;
        var p = Object.create(a);
        p.y = 2;
        console.log(p.x);

3

var a = {};
        a.x = 1;
        var p = Object.create(a);
        p.y = 2;
        console.log("x" in p); //true

4

var a = {};
        a.x = 1;
        var p = Object.create(a);
        p.y = 2;
        console.log("x" in p); //true
        console.log(p.hasOwnProperty("x")); //false

5

var a = {
            x:1,
            get getx() {return this.x;},
            set setx(arg) {
                return this.x = arg;
            }
        }
        console.log(a.x);
        a.x = 100;
        console.log(a.x);

6

var a = {
            x:1,
            get getx() {return this.x;},
            set setx(arg) {
                return this.x = arg;
            }
        }
        Object.freeze(a);
        a.x = 100;
        console.log(a.x); //1

Javascript对象的技巧和陷阱

标签：javascript   对象   继承   

原文地址：http://blog.csdn.net/atvance016/article/details/40709505