1--TEST-- 2callback function returns non modified value 3--SKIPIF-- 4<?php if (!extension_loaded("filter")) die("skip"); ?> 5--FILE-- 6<?php 7function callback($var) { 8 return $var; 9} 10$var = "test"; 11var_dump(filter_var($var, FILTER_CALLBACK, array('options'=>'callback'))); 12?> 13--EXPECT-- 14string(4) "test" 15