note 124027 added to function.strrpos

The description of offset is wrong. Here’s how it works, with supporting examples. Offset effects both the starting point and stopping point of the search. The direction is always right to left. (The description wrongly says PHP searches left to right when offset is positive.) Here’s how it works: When offset is positive, PHP searches right to left from the end of haystack to offset. This ignores the left side of haystack. When offset is negative, PHP searches right to left, starting offset bytes from the end, to the start of haystack. This ignores the right side of haystack. Example 1: $foo = ‘aaaaaaaaaa’; var_dump(strrpos($foo, 'a', 5)); Result: int(10) Example 2: $foo = "aaaaaa67890"; var_dump(strrpos($foo, 'a', 5)); Result: int(5) Conclusion: When offset is positive, PHP searches right to left from the end of haystack. Example 3: $foo = "aaaaa567890"; var_dump(strrpos($foo, 'a', 5)); Result: bool(false) Conclusion: When offset is positive, PHP stops searching at offset. Example 4: $foo = ‘aaaaaaaaaa’; var_dump(strrpos($foo, 'a', -5)); Result: int(6) Conclusion: When offset is negative, PHP searches right to left, starting offset bytes from the end. Example 5: $foo = "a234567890"; var_dump(strrpos($foo, 'a', -5)); Result: int(0) Conclusion: When offset is negative, PHP searches right to left, all the way to the start of haystack. ---- Server IP: 208.43.231.9 Probable Submitter: 119.81.81.244 (proxied: 71.218.37.158) ---- Manual Page -- http://php.net/manual/en/function.strrpos.php Edit -- https://master.php.net/note/edit/124027 Del: integrated -- https://master.php.net/note/delete/124027/integrated Del: useless -- https://master.php.net/note/delete/124027/useless Del: bad code -- https://master.php.net/note/delete/124027/bad+code Del: spam -- https://master.php.net/note/delete/124027/spam Del: non-english -- https://master.php.net/note/delete/124027/non-english Del: in docs -- https://master.php.net/note/delete/124027/in+docs Del: other reasons-- https://master.php.net/note/delete/124027 Reject -- https://master.php.net/note/reject/124027 Search -- https://master.php.net/manage/user-notes.php