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Exceptionluo
V2EX    Javascript

对执行结果无法理解 ,求助~

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  •   Exceptionluo 2018-04-24 23:01:11 +08:00 3663 次点击
    这是一个创建于 2794 天前的主题,其中的信息可能已经有所发展或是发生改变。
    var My = {} My.namespace = function (name) { var parts = name.split(',') var current = My; for (i in parts) { if (!current[parts[i]]) { current[parts[i]] = {} console.log(current, My, i, current === My) } current = current[parts[i]] } } My.namespace('dom,style') console.log(My) 代码如上,对最终的执行结果无法理解 为何 style:{}会挂载到 My 上面呢 每次 current[parts[i]] = {} 执行后 再执行 current = current[parts[i]] current 被设置成{} 他又是如何与 My 保持关联的呢 
    5 条回复    2018-04-24 23:26:25 +08:00
    chenstack
        1
    chenstack  
       2018-04-24 23:08:46 +08:00
    不太理解所说的 style:{}挂载到 My 上面,第一次循环相当于 My.dom = {}; current = My.dom; 第二次循环相当于 My.dom.style = {};
    Exceptionluo
        2
    Exceptionluo  
    OP
       2018-04-24 23:21:26 +08:00
    @chenstack 为什么第二次循环相当于 My.dom.style = {};呢 就是这里不理解
    rabbbit
        3
    rabbbit  
       2018-04-24 23:21:50 +08:00
    第一次循环结束后
    current 指向 My["dom"],值是 {}
    nanyang24
        4
    nanyang24  
       2018-04-24 23:25:49 +08:00
    @Exceptionluo 第一次循环之后 `current = My.dom`。第二次循环:`current[parts[1]] = {}` 相当于 `My.dom.style = {}`
    Exceptionluo
        5
    Exceptionluo  
    OP
       2018-04-24 23:26:25 +08:00
    @rabbbit @chenstack 瞬间就懂啦 感谢
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