Rechercher une fonction PHP

strrpos

Contents

(PHP 4, PHP 5, PHP 7)

strrpos — Find the position of the last occurrence of a substring in a string

Description

strrpos ( string $haystack , mixed $needle [, int $offset = 0 ] ) : int

Find the numeric position of the last occurrence of needle in the haystack string.

PHP: strrpos - Manual Home of Manuel PHP  Contents Haut

Parameters

haystack

The string to search in.

needle

If needle is not a string, it is converted to an integer and applied as the ordinal value of a character. This behavior is deprecated as of PHP 7.3.0, and relying on it is highly discouraged. Depending on the intended behavior, the needle should either be explicitly cast to string, or an explicit call to chr() should be performed.

offset

If zero or positive, the search is performed left to right skipping the first offset bytes of the haystack.

If negative, the search is performed right to left skipping the last offset bytes of the haystack and searching for the first occurrence of needle.

Note:

This is effectively looking for the last occurrence of needle before the last offset bytes.

PHP: strrpos - Manual Home of Manuel PHP  Contents Haut

Return Values

Returns the position where the needle exists relative to the beginning of the haystack string (independent of search direction or offset).

Note: String positions start at 0, and not 1.

Returns FALSE if the needle was not found.

Warning

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

PHP: strrpos - Manual Home of Manuel PHP  Contents Haut

Examples

Example #1 Checking if a needle is in the haystack

It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:

<?php

$pos = strrpos($mystring, "b");
if ($pos === false) { // note: three equal signs
    // not found...
}

?>

Example #2 Searching with offsets

<?php
$foo = "0123456789a123456789b123456789c";

// Looking for '0' from the 0th byte (from the beginning)
var_dump(strrpos($foo, '0', 0));

// Looking for '0' from the 1st byte (after byte "0")
var_dump(strrpos($foo, '0', 1));

// Looking for '7' from the 21th byte (after byte 20)
var_dump(strrpos($foo, '7', 20));

// Looking for '7' from the 29th byte (after byte 28)
var_dump(strrpos($foo, '7', 28));

// Looking for '7' right to left from the 5th byte from the end
var_dump(strrpos($foo, '7', -5));

// Looking for 'c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, 'c', -2));

// Looking for '9c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, '9c', -2));
?>

The above example will output:

int(0)
bool(false)
int(27)
bool(false)
int(17)
bool(false)
int(29)

PHP: strrpos - Manual Home of Manuel PHP  Contents Haut

See Also

  • strpos() - Find the position of the first occurrence of a substring in a string
  • stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
  • strripos() - Find the position of the last occurrence of a case-insensitive substring in a string
  • strrchr() - Find the last occurrence of a character in a string
  • substr() - Return part of a string

Find a PHP function

English translation

You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.

If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.

Thank you in advance.

Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-function.strrpos.html

The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.

References

  1. View the html document Language of the document:fr Manuel PHP : http://php.net

These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.

Contents Haut