function_exists: see functions after it?

[Anon]

I want to do something like this:

if(function_exists('coolfunction')) {
blah;
}

...but "coolfunction" isn't defined until 300 lines later in the code. I thought that in PHP 4, functions could now be anywhere in the code and work no matter where they were called. Is that true? If so, shouldn't my "if" statement execute?

If it is not true, is there anything I can do to make it true? For instance, would adding the Zend optimizer or cache change the default behavior?

[leera]

when a xxx.php is begin,the apache_model first check all content in xxx.php include all it's "include or require",wherever a function in this xxx.php is been declared ,u can use it freely.