--TEST-- string offset 004 --FILE-- --EXPECTF-- string(15) "abCdefghijklmno" string(15) "abCZefghijklmno" string(15) "abCZefghijPlmno" string(15) "abCZefghijPQmno" Warning: Illegal string offset: -20 in %sstr_offset_004.php on line %d string(15) "abCZefghijPQmno" string(15) "AbCZefghijPQmno" string(21) "AbCZefghijPQmno N" string(21) "AbCZefghijPQmno UN" string(21) "AbCZefghijPQmno nUN"