IE的Object.defineProperty

Question

var o = {}; // Creates a new object

使用带有数据属性描述符的defineProperty添加的对象属性示例

Object.defineProperty(o, "a", {value : 37,
                               writable : true,
                               enumerable : true,
                               configurable : true});

如何实现IE7-8？(属性可写、可枚举、可配置)

Answer 1

if (!Object.defineProperty) {
        Object.defineProperty = function (obj, prop, descriptor) {
            if (arguments.length < 3) { // all arguments required
                throw new TypeError("Arguments not optional");
            }

            prop += ""; // convert prop to string
            ...