Javascript eval results in “undefined function” but works in Firebug

Question

I'm wondering why when I call: eval("myFunc(1,2,3)") in the Firebug console on a rendered page, the function executes properly, but when I call the same eval within by javascript within then page, I get a " is not defined" error that pops up in the Firebug console. Part of my problem is that I don't have control over the incoming HTML/JS and I can't seem to find where the function is defined. So I guess my questions are, why am I getting that error and how can I find where the function I'm trying to call is defined? If I pull up the page source, I can see calls to the function but I don't see where it is defined.

Answer 1

如果您查看源代码，那么您也应该能够在源代码中看到任何JS以及任何附加的js文件-您应该能够下载它们并在编辑器中将其打开，然后进行查找。

Answer 2

The function is probably defined in an external file. In firebug, if you just type out myFunc (without paranthesis) you should be able to get a clickable link to the source.

The reason it's not working in your eval-script, is probably that it's being executed before the function is defined. Try defering it by, say, putting it in a page load or domready event listener.