![]() If my math is off, please feel free to correct. Return ( $pos = false )? false :( $length - $pos - strlen ( $needle ) ) $pos = strpos ( strrev ( $haystack ), strrev ( $needle ), $offset ) 0 )?( $length - $offset ): abs ( $offset ) ![]() Here is an example of backwards stepping through instances of a string with this function: Negative offsets search backwards from the position of the character that many characters from the end of the string. Positive offsets search backwards from the supplied string index. ![]() This version I have treats the offset very simply: I've got a simple method of performing a reverse strpos which may be of use. This ignores the right side of haystack.Ĭonclusion: When offset is positive, PHP searches right to left from the end of haystack.Ĭonclusion: When offset is positive, PHP stops searching at offset.Ĭonclusion: When offset is negative, PHP searches right to left, starting offset bytes from the end.Ĭonclusion: When offset is negative, PHP searches right to left, all the way to the start of haystack. When offset is negative, PHP searches right to left, starting offset bytes from the end, to the start of haystack. When offset is positive, PHP searches right to left from the end of haystack to offset. (The description wrongly says PHP searches left to right when offset is positive.) Offset effects both the starting point and stopping point of the search. Here’s how it works, with supporting examples. If instead you used strrpos($text, " ", 50), then you would find the last space between the 50th character and the end of the string, which may not have been what you were intending. If, for example, you want to find the last space in a string before the 50th character, you'll need to do something like this: If the needle is farther away from the end of the string, it won't be found. If offset is negative, then strrpos only operates on that many characters at the end of the string. This will usually have the same results as not specifying an offset, unless the only occurences of needle are before offset (in which case specifying the offset won't find the needle). ![]() If offset is positive, then strrpos only operates on the part of the string from offset to the end. This is confusing if you think of strrpos as starting at the end of the string and working backwards. Negative values will stop searching at an arbitrary point prior to the end of the string." It says, "offset may be specified to begin searching an arbitrary number of characters into the string. The documentation for 'offset' is misleading. Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search
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