I am trying to figure out the mechanics of this plugin in WordPress. I have a preg_match_all function that looks like this:
preg_match_all(\'/(?<=\\\\[\\\
If I understand this correctly, count($matches[0] assumes there is only one match in $content.
Not quite; $matches[0] represents the array of matches in of the whole regular expression (as opposed to, say, $matches[1], which would be the array of matches in the first match group of the regular expression). Thus, count($matches[0]) is the number of matches in he first match group.
You could do what you've said and rewrite the for loop as a foreach loop, but this likely won't change anything, as both methods should traverse all elements in $matches[0]. Are you certain that the results you're looking for are matched in your regular expression?