ConFoo 2025

strrchr

(PHP 4, PHP 5, PHP 7, PHP 8)

strrchrTrouve la dernière occurrence d'un caractère dans une chaîne

Description

strrchr(string $haystack, string $needle, bool $before_needle = false ): string|false

Retourne le segment de la chaîne haystack qui commence avec la dernière occurrence de needle, jusqu'à la fin de la chaîne haystack.

Liste de paramètres

haystack

La chaîne dans laquelle on doit chercher.

needle

Si needle contient plus d'un caractère, seul le premier sera utilisé. Ce comportement est différent de celui de strchr().

Antérieur à PHP 8.0.0, si needle n'est pas une chaîne de caractères, elle est convertie en un entier et appliqué en tant que valeur ordinal d'un caractère. Ce comportement est obsolète à partir de PHP 7.3.0, et se fier à celui-ci est fortement déconseillé. En fonction du comportement attendu, needle doit être transtypé explicitement en une chaîne de caractère, ou un appel explicite à chr() doit être exécuté.

before_needle

Si true, strrchr() renvoie la partie du haystack avant la dernière occurrence de needdle (à l'exclusion de cette dernière).

Valeurs de retour

Retourne la portion de la chaîne, ou false si needle n'est pas trouvé.

Historique

Version Description
8.3.0 Le paramètre before_needle a été ajouté.
8.0.0 needle accepte désormais une chaîne vide.
8.0.0 Passing an entier as needle is no longer supported.
7.3.0 Passer un entier comme before_needle a été rendu obsolète.

Exemples

Exemple #1 Exemple avec strrchr()

<?php
$ext
= strrchr('somefile.txt', '.');
echo
"extension de fichier: $ext \n";
$ext = $ext ? strtolower(substr($ext, 1)) : '';
echo
"extension de fichier: $ext";
?>

Résultat de l'exemple ci-dessus est similaire à :

extension de fichier: .txt
extension de fichier: txt

Notes

Note: Cette fonction gère les chaînes binaires.

Voir aussi

  • strstr() - Trouve la première occurrence dans une chaîne
  • strrpos() - Cherche la position de la dernière occurrence d'une sous-chaîne dans une chaîne

add a note

User Contributed Notes 8 notes

up
31
matthewkastor at live dot com
13 years ago
<?php
/**
* Removes the preceeding or proceeding portion of a string
* relative to the last occurrence of the specified character.
* The character selected may be retained or discarded.
*
* Example usage:
* <code>
* $example = 'http://example.com/path/file.php';
* $cwd_relative[] = cut_string_using_last('/', $example, 'left', true);
* $cwd_relative[] = cut_string_using_last('/', $example, 'left', false);
* $cwd_relative[] = cut_string_using_last('/', $example, 'right', true);
* $cwd_relative[] = cut_string_using_last('/', $example, 'right', false);
* foreach($cwd_relative as $string) {
* echo "$string <br>".PHP_EOL;
* }
* </code>
*
* Outputs:
* <code>
* http://example.com/path/
* http://example.com/path
* /file.php
* file.php
* </code>
*
* @param string $character the character to search for.
* @param string $string the string to search through.
* @param string $side determines whether text to the left or the right of the character is returned.
* Options are: left, or right.
* @param bool $keep_character determines whether or not to keep the character.
* Options are: true, or false.
* @return string
*/
function cut_string_using_last($character, $string, $side, $keep_character=true) {
$offset = ($keep_character ? 1 : 0);
$whole_length = strlen($string);
$right_length = (strlen(strrchr($string, $character)) - 1);
$left_length = ($whole_length - $right_length - 1);
switch(
$side) {
case
'left':
$piece = substr($string, 0, ($left_length + $offset));
break;
case
'right':
$start = (0 - ($right_length + $offset));
$piece = substr($string, $start);
break;
default:
$piece = false;
break;
}
return(
$piece);
}
?>
up
12
sekati at gmail dot com
18 years ago
just a small addition to carlos dot lage at gmail dot com note which makes it a bit more useful and flexible:

<?php
// return everything up to last instance of needle
// use $trail to include needle chars including and past last needle
function reverse_strrchr($haystack, $needle, $trail) {
return
strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) + $trail) : false;
}
// usage:
$ns = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 0));
$ns2 = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 1));
echo(
$ns . "<br>" . $ns2);
?>
up
6
dchris1 at bigpond dot net dot au
20 years ago
The function provided by marcokonopacki at hotmail dot com isn't really a reverse-version of strrchr(), rather a reverse version of strchr(). It returns everything from the start of $haystack up to the FIRST instance of the $needle. This is basically a reverse of the behavior which you expect from strchr(). A reverse version of strrchr() would return everything in $haystack up to the LAST instance of $needle, eg:

<?php
// reverse strrchr() - PHP v4.0b3 and above
function reverse_strrchr($haystack, $needle)
{
$pos = strrpos($haystack, $needle);
if(
$pos === false) {
return
$haystack;
}
return
substr($haystack, 0, $pos + 1);
}
?>

Note that this function will need to be modified slightly to work with pre 4.0b3 versions of PHP due to the return type of strrpos() ('0' is not necessarily 'false'). Check the documentation on strrpos() for more info.

A function like this can be useful for extracting the path to a script, for example:

<?
$string = "/path/to/the/file/filename.php";

echo reverse_strrchr($string, '/'); // will echo "/path/to/the/file/"
?>
up
6
readless at gmx dot net
18 years ago
to: repley at freemail dot it

the code works very well, but as i was trying to cut script names (e.g.: $_SERVER["SCRIPT_NAME"] => /index.php, cut the string at "/" and return "index.php") it returned nothing (false). i've modified your code and now it works also if the needle is the first char.
- regards from germany

<?php
//strxchr(string haystack, string needle [, bool int leftinclusive [, bool int rightinclusive ]])
function strxchr($haystack, $needle, $l_inclusive = 0, $r_inclusive = 0){
if(
strrpos($haystack, $needle)){
//Everything before last $needle in $haystack.
$left = substr($haystack, 0, strrpos($haystack, $needle) + $l_inclusive);

//Switch value of $r_inclusive from 0 to 1 and viceversa.
$r_inclusive = ($r_inclusive == 0) ? 1 : 0;

//Everything after last $needle in $haystack.
$right = substr(strrchr($haystack, $needle), $r_inclusive);

//Return $left and $right into an array.
return array($left, $right);
} else {
if(
strrchr($haystack, $needle)) return array('', substr(strrchr($haystack, $needle), $r_inclusive));
else return
false;
}
}
?>
up
4
freakinunreal at hotmail dot com
18 years ago
to marcokonopacki at hotmail dot com.

I had to make a slight change in your function for it to return the complete needle inclusive.

// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{

// Returns everything before $needle (inclusive).
//return substr($haystack,0,strpos($haystack,$needle)+1);
// becomes
return substr($haystack,0,strpos($haystack,$needle)+strlen($needle));
}

Note: the +1 becomes +strlen($needle)

Otherwise it only returns the first character in needle backwards.
up
7
Primo Anderson Do S?tio
19 years ago
$filename = 'strrchr_test.php';
print strrchr( $filename, '.' );

Result:
.php

$other_filename = 'strrchr_test.asp.php';
print strrchr( $other_filename, '.' );

Result:
.php
up
0
marcokonopacki at hotmail dot com
21 years ago
<?

// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{

// Returns everything before $needle (inclusive).
return substr($haystack,0,strpos($haystack,$needle)+1);

}

$string = "FIELD NUMBER(9) NOT NULL";

echo strrrchr($string,")"); // Will print FIELD (9)

?>
up
-5
carlos dot lage at gmail dot com
19 years ago
I used dchris1 at bigpond dot net dot au 's reverse strrchr and reduced it to one line of code and fixed it's functionality - the real strrchr() returns FALSE if the needle is not found, not the haystack :)

<?php
// reverse strrchr()
function reverse_strrchr($haystack, $needle)
{
return
strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) +1 ) : false;
}
?>
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