通过“功能”对象在JavaScript

Question

我有这个项目，我想合并“功能”对象循环（与JSON对象 - 一个对象文本）与现有对象。我想获得“公开可见”的属性。然而，当我在环路做，他们不露面。他们不触发console.log()内。我如何得到它们？

//obj passed to extend() by external caller 
//this is what obj it looked like when i console.log()'ed it 
obj = function() { 

    //skip these private ones 
    var imPrivate = 'i should not be included'; 
    function imGetter() {} 

    //i want these guys below: 
    this.getter = imGetter; 
    this.imPublic = "i should be included"; 

} 

function extend(obj){ 
    console.log('i can see here'); 

    for (var key in obj) { 
     console.log('you cannot see here'); 
    }​ 

    //...more of our code here 
} 

Answer 1

这些属性不存在，直到你调用该函数。

一旦你var foo = new obj();然后你会看到the properties（在foo）。

或者，动议设置属性所以它是outside the function的代码。

Answer 2

你可以把它的自我执行：

var obj={}; 
(function(ns) { //skip these private ones 
    var imPrivate = 'i should not be included'; 

    function imGetter() {}; 
    //i want these guys below: 
    ns.getter = imGetter; 
    ns.imPublic = "i should be included"; 
})(obj) 
console.log('i can see here'); 
for (var key in obj) { 
    console.log('you cannot see here '+key+" holds:"+obj[key]); 
}