记一IE6,7,8中出现的bug

最近项目中写了段代码，做的事情依赖于某些异步加载的组件，由于异步的操作比较多，于是采用了一种偷懒的做法。。用轮询去检测某一组件是否加载完，但在同时检测两个组件时IE8-下出问题了。额。。还是来段事例代码吧：

<p id="testp"></p>

<script>
var i = 0;
(function fn() {
    document.getElementById('testp').innerHTML += 'from 1st fn(i == ' + i + ')<br />';
if (i++ < 5) {
        setTimeout(fn, 100);
    }
})();
(function fn() {
    document.getElementById('testp').innerHTML += 'from 2nd fn(i == ' + i + ')<br />';
if (i++ < 5) {
        setTimeout(fn, 100);
    }
})();
</script>

我期望的输出是：

from 1st fn(i == 0)
from 2nd fn(i == 1)
from 1st fn(i == 2)
from 2nd fn(i == 3)
from 1st fn(i == 4)
from 2nd fn(i == 5)
from 1st fn(i == 6)

我自测时IE9, FF, CHROME 也确实是这样的。可IE8下却不同：

from 1st fn(i == 0)
from 2nd fn(i == 1)
from 2nd fn(i == 2)
from 2nd fn(i == 3)
from 2nd fn(i == 4)
from 2nd fn(i == 5)
from 2nd fn(i == 6)

后面的fn把前面的覆盖了！可后来仔细想想这两个fn貌似是在同一作用域下的，把前者覆盖也合情合理。呵呵，还是取两个不一样的函数名吧，避免这种有可能产生歧义的写法。

转载于:https://www.cnblogs.com/ecma/archive/2012/02/22/2363676.html