In contrast to strpos(), the return value of iconv_strrpos() is the number of characters that appear before the needle, rather than the offset in bytes to the position where the needle has been found.
haystack
The entire string.
needle
The searched substring.
charset
If charset
parameter is omitted,
string
are assumed to be encoded in
iconv.internal_encoding.
If haystack
or needle
is
not a string, it is converted to a string and applied as the ordinal
value of a character.