Escaped explode/implode function
Not bad.  I just have a few nitpicks.

You can iterate over characters of a string directly without splitting it into an array first:

for ($i = 0; $i &lt; strlen($string); $i++) {
    $char = $string[$i];
    ...
}


I believe that the PHP interpreter isn't smart enough to recognize that strlen($string) is invariant, so you might get better performance with

$strlen = strlen($string);
for ($i = 0; $i &lt; $strlen; $i++) {
    $char = $string[$i];
    ...
}


I find the else if in escapedExplode() slightly jarring.  Either use if and continue everywhere, or if, else if, else if, else without continue.