<?php
$str = "Hello this is dummy.test. in this string
any character, any special character can appear. it is not a fixed type
text and predefined. this string will not read manually check by the
Programmer.Sorry for the bad English.";
$test = strrpos($str, 'test');
$dummy = strrpos($str, 'dummy', -strlen($str) - $test);
echo $dummy;
Fatal error: Uncaught ValueError: strrpos(): Argument #3 ($offset) must be contained in argument #1 ($haystack) in /in/JSsaB:9
Stack trace:
#0 /in/JSsaB(9): strrpos('Hello this is d...', 'dummy', -243)
#1 {main}
thrown in /in/JSsaB on line 9
Process exited with code 255.