mb_strrpos throws a warning if $haystack is empty.
strrpos simply returns FALSE.
This is something to be wary of if overloading the mb functions.
(PHP 4 >= 4.0.6, PHP 5)
mb_strrpos — Find position of last occurrence of a string in a string
Performs a multibyte safe strrpos() operation based on the number of characters. needle position is counted from the beginning of haystack. First character's position is 0. Second character position is 1.
The string being checked, for the last occurrence of needle
The string to find in haystack.
The encoding parameter is the character encoding. If it is omitted, the internal character encoding value will be used.
Returns the numeric position of the last occurrence of needle in the haystack string. If needle is not found, it returns FALSE.
|5.2.0||Added the optional parameter offset.|
Note: The encoding parameter was moved from the third position to the fourth in PHP 5.2.0. For backward compatibility, encoding can be specified as the third parameter, but doing so is deprecated and will be removed in the future.
The internal encoding or the character encoding specified by mb_regex_encoding() will be used as the character encoding for this function.